Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.59 (MIP)
 4,906 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The myelosuppressive effects of human chemokines were evaluated in vitro on normal myeloid progenitors obtained from bone marrow and cord blood, on bone marrow progenitors from patients with acute or chronic leukemia, on proliferation of human factor-dependent cell line M07e, and in vivo on myelopoiesis in mice. Preincubation of human MIP-1 alpha, MIP-2 alpha, interleukin (IL)-8, platelet factor (PF) 4, monocyte chemotactic and activating factor (MCAF), and interferon-inducible protein-10 (IP-10) in an acetonitrile (ACN) solution significantly enhanced the specific activity of these chemokines for in vitro suppression of granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells stimulated to proliferate with a colony stimulating factor plus steel factor (SLF). Combinations of any two of these ACN-treated chemokines synergized to suppress colony formation of CFU-GM, BFU-E, and CFU-GEMM at chemokine concentrations below that at which combinations of non-ACN treated chemokines are active. Cord blood progenitors, as previously reported, were in a slow or noncycling state and nonresponsive to inhibition by chemokines. However, after suspension culture with GM-CSF, IL-3, and SLF, they were placed into rapid cell cycle and were responsive to inhibition by ACN-treated chemokines. Low doses of these ACN-pretreated chemokines were active in vivo in suppressing absolute numbers and cycling status of femoral marrow CFU-GM, BFU-E, and CFU-GEMM in C3H/HeJ mice. Other chemokines, alone and in combination, including MIP-1 beta, MIP-2 beta, GRO-alpha NAP-2, and RANTES, were inactive in vitro and in vivo whether or not they were pretreated with ACN. While heterogeneity in responsiveness of CFU-GM from different patients with leukemia to suppression by ACN-treated chemokines was apparent, if the patients had CFU-GM responsive to one of the active chemokines these cells were responsive to the other active chemokines; if patient CFU-GM were not responsive to one of the chemokines, they were not responsive to the other active chemokines. M07e colony-forming cells were responsive to the growth-inhibiting effects of the active ACN-treated chemokines, alone and in combination, but these effects were rapidly reversible and sustained only by multiple daily additions of chemokines. These results should be of value in considering these chemokines for potential clinical use and for assessment of their mechanisms of action, alone and in combination.
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PMID:Human chemokines: enhancement of specific activity and effects in vitro on normal and leukemic progenitors and a factor-dependent cell line and in vivo in mice. 749 26

We have previously characterized the proliferative response of primitive CD34+ cells, purified from adult bone marrow, umbilical cord blood, and fetal liver, to a mixture of hematopoietic stimulators (steel factor [SF], interleukin-3 [IL-3], IL-6, and erythropoietin [Epo]) in serum-free liquid cultures. In the present study, we assessed the effects of the hematopoietic inhibitors, macrophage inflammatory protein-1 alpha (MIP-1 alpha), transforming growth factor-beta (TGF-beta), and tumor necrosis factor-alpha (TNF-alpha), on the cytokine-induced proliferation of three different CD34+ cell subpopulations derived from cord blood and on total CD34+ cells derived from fetal liver. In cultures of cord blood cells, addition of MIP-1 alpha inhibited the numerical expansion of primitive CD34+ cells (CD34+ CD45RAlow CD71low cells) without inhibiting the proliferation of more mature subpopulations enriched for myeloid (CD34+ CD45RA+ CD71low cells) or erythroid (CD34+ CD45RAlow CD71+ cells) progenitors. TGF-beta significantly reduced the proliferation of all three subpopulations, although its effects were more pronounced on cells of the erythroid lineage, particularly immature erythroid progenitors. Similarly, TNF-alpha preferentially inhibited total nucleated and CD34+ cell production in the subpopulation enriched for erythroid cells. However, in contrast to TGF-beta, TNF-alpha preferentially inhibited the proliferation of more mature erythroid progenitors. In a separate set of experiments, MIP-1 alpha, TGF-beta, and TNF-alpha were added to cultures of total CD34+ cells purified from fetal liver. In keeping with the fact that the majority of the progenitors contained in these cells were erythroid progenitors, the inhibitory effects of the three cytokines were similar to those observed in cultures of CD34+ CD45RAlow CD71+ cord blood cells. The results of the present study demonstrate that MIP-1 alpha, TGF-beta, and TNF-alpha have the capacity to modulate cytokine-induced proliferation of cord blood and fetal liver progenitors. The differential effects of these three cytokines confirm their pleiotropic nature as regulators of hematopoiesis.
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PMID:Differential effects of the hematopoietic inhibitors MIP-1 alpha, TGF-beta, and TNF-alpha on cytokine-induced proliferation of subpopulations of CD34+ cells purified from cord blood and fetal liver. 753 84

The aim of this study was to compare the inhibitory effect of the tetrapeptide AcSDKP, tumor necrosis factor-alpha (TNF-alpha), which contains the sequence of the peptide, transforming growth factor-beta (TGF-beta), and macrophage inflammatory protein-1 alpha (MIP-1 alpha) on sorted CD34+ cells using both proliferation and clonogenic assays. Although a short treatment with any of the molecules decreased the growth of colony-forming unit granulocyte/macrophage (CFU-GM) and burst-forming unit-erythroid (BFU-E) progenitors (except for TNF-alpha as it is a greater inhibitor for CFU-GM), further experiments using a 6-day liquid culture in the presence of a combination of growth factors (recombinant human interleukin-3 [rhIL-3], IL-6, IL-1 beta, GM colony-stimulating factor [GM-CSF], G-CSF, erythropoeitin [Epo], and stem cell factor [SCF]) allowed us to determine a number of differences between their effects: 1) TGF-beta and TNF-alpha induced a stronger decrease in the proliferation and clonogenicity of CD34+ subsets than MIP-1 alpha and AcSDKP, 2) the dose-response curves appeared different, and 3) contrary to TGF-beta and TNF-alpha, AcSDKP and MIP-1 alpha required repeated addition to induce inhibition. Therefore, our data clearly show that while the inhibitory effect of TNF-alpha and AcSDKP appeared to be different, there is a close similarity in the effect of AcSDKP and MIP-1 alpha on normal human progenitor response to the combination of growth factors used.
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PMID:Comparison of the inhibitory effect of AcSDKP, TNF-alpha, TGF-beta, and MIP-1 alpha on marrow-purified CD34+ progenitors. 753 83

Perfusion cultures of human bone marrow mononuclear cells (BMMNC) provide a unique in vitro model of hematopoiesis, supporting growth of both accessory and hematopoietic elements. In this study, bioreactors were used to analyze the consumption and production of growth factors (GFs) in relation to each other and to the cells produced. The exogenously added GFs interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), stem cell factor (SCF), and erythropoietin (Epo) each exhibited different, but reproducible, consumption kinetics. Epo and IL-3 were consumed slowly for the first 5-7 days, and then the consumption rate of both increased. Epo consumption reached a plateau by day 10, whereas IL-3 consumption continued to increase. Consumption of SCF was similar to that of Epo, but began 2-3 days earlier. GM-CSF was consumed throughout the culture period in an accelerating manner. Consumption of SCF and Epo were related, because omission of Epo from the growth medium reduced SCF consumption by 53% and omission of SCF reduced Epo consumption by 82%. A reproducible relationship between cumulative GF consumption and total cell production was observed. Epo was most potent, with 5900 molecules consumed per cell produced, whereas 69,400 molecules of SCF were consumed per cell generated. More specifically, Epo consumption was correlated (r = 0.92 and 0.96) with the number of glycophorin A-positive (glyA+) cells produced, and the rate of Epo consumption varied with the progression of cells through the erythroid lineage. Consequently, measurement of GF consumption rates may be useful for quantifying the types of cells present in a culture. Endogenous GF production was also examined. G-CSF and MIP-1 alpha were present at high levels during the first 4 days but then declined rapidly. LIF first appeared in the second week and steadily increased thereafter. Omission of SCF from the medium allowed the detection of endogenous SCF production, and the kinetics was similar to that of LIF. IL-6 production was biphasic, with a peak and decline in week 1 and an increase during week 2. TGF-beta was below the level of detection in these cultures. The results suggest that perfusion supports accessory and hematopoietic elements which interact and therefore represent a partially functional tissue ex vivo. This system provides a useful model for studying relationships within GF networks and for elucidating the conditions that result in primitive cell expansion ex vivo.
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PMID:Growth factor consumption and production in perfusion cultures of human bone marrow correlate with specific cell production. 758 82

The influence of macrophage inflammatory protein-1 alpha (MIP-1 alpha) on cloning efficiency of human erythroid progenitors was evaluated. In our hands, in performed experiments in serum supplemented as in serum free cloning culture systems we did not observe any effect of MIP-1 alpha on erythroid colony formation by human CD34+ bone marrow cells. Therefore, our data did not confirm the possibility of the direct role of MIP-1 alpha in the pathogenesis of the anaemia of chronic disease.
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PMID:[Effect of macrophage inflammatory protein-1 alpha (MIP-1 alpha) on human erythropoiesis in vitro--clinical implications]. 765 22

To determine the role of infected marrow accessory cells in the pathogenesis of viral-associated hematologic disorders, we evaluated whether feline leukemia virus (FeLV) infection alters the cytoadhesive properties of long-term marrow culture (LTMC) stromal cells, the support of stromal-associated progenitors in LTMCs, and the production of progenitor growth-promoting and -inhibiting activities by marrow stromal cells. Our previous studies demonstrated that LTMCs containing FeLV-infected stromal cells generated two- to three-fold higher numbers of total nonadherent cells and nonadherent granulocyte-macrophage progenitors (CFU-GM) compared with uninfected LTMCs. In the present studies, CFU-GM and primitive erythroid progenitors (BFU-E) bound equivalently to FeLV-infected or uninfected LTMC stromal cells in a 2-hour adherence assay. In recharge LTMC studies, the numbers of adherent CFU-GM maintained in cultures containing stromal cells infected with FeLV-A/61E were not significantly different from controls (range 84-191% of uninfected control cultures, p > 0.1); however, the percentages of adherent CFU-GM in S phase of the cell cycle were consistently increased (range 42-62% compared with controls, range 5-23%). FeLV infection had no significant effect on the cell-cycle status of the nonadherent CFU-GM in LTMCs. Agar co-culture assays revealed that multilineage colony-stimulating activity was constitutively and equivalently produced by feeder cell layers consisting of either uninfected or FeLV-infected irradiated heterogeneous LTMC stromal cells, homogeneous marrow stromal fibroblasts, or a fibroendothelial marrow stromal cell line. However, FeLV infection significantly attenuated the soluble progenitor growth-inhibitory activity associated with higher densities of these stromal cells. Assays of conditioned medium from cultures of irradiated stromal cells demonstrated that FeLV infection or hydrocortisone exposure decreased the utilization of glucose, the production of acidic metabolic products, and the constitutive production of active and latent transforming growth factor beta (TGF-beta) bioactivity and TGF-beta 2 immunoreactivity. Levels of macrophage inflammatory protein 1 alpha (MIP-1 alpha) and tumor necrosis factor alpha (TNF-alpha) were undetectable and unchanged in CM samples. Together, these observations suggest that downmodulation of TGF-alpha and/or the basal metabolic status of stromal cells may be responsible for the high basal proliferative activity of adherent CFU-GM in FeLV-infected LTMCs, and by extension, that retroviral infection in vivo could alter hematopoiesis by perturbing the progenitor growth-regulatory and -supportive function of marrow stromal cells.
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PMID:Feline leukemia virus infection downmodulates the production of growth-inhibitory activity by marrow stromal cells. 765 28

In the present study, we investigated the ability of the tetrapeptide NAc-Ser-Asp-Lys-Pro-OH (AcSDKP), a reported inhibitor of primitive hematopoietic cells, to influence the proliferative behavior of primitive normal and chronic myeloid leukemia (CML) progenitor cells in the adherent layer of long-term cultures (LTCs). Addition of > or = 50 ng/mL of AcSDKP to LTCs of normal cells at the time of the regular weekly half-medium change selectively and reversibly decreased the proportion of high proliferative potential erythroid and granulopoietic progenitors in the adherent layer that were in S-phase without changing their numbers, but had no effect on either the cycling activity or number of analogous (neoplastic) cells in the adherent layer of CML LTCs. Specificity of the effect of AcSDKP on primitive normal progenitors was demonstrated by the finding that a similar addition of either the control peptide, AcSDKE, or 100 ng/mL of tumor necrosis factor-alpha (TNF-alpha, which contains the SDKP sequence), or SDKP itself (at 300 ng/mL) did not inhibit the proliferation of primitive normal progenitors in LTC adherent layers. Incorporation of > or = 30 ng/mL of AcSDKP (but not the related control peptide, AcSDKE) directly into methylcellulose cultures of normal marrow cells resulted in a dose-dependent suppression of colony formation, which was not seen in similar studies with CML marrow or after removal of adherent cells from normal marrow. Additional experiments showed that the inhibitory effect of AcSDKP on primitive normal progenitor cycling in the LTC system could be overcome by the simultaneous addition of macrophage inflammatory protein-1 beta (MIP-1 beta); an antagonist of MIP-1 alpha. The apparent differential effect of AcSDKP on primitive normal and CML progenitors may thus be a secondary consequence of the differential responsiveness of these cells to MIP-1 alpha for another molecule antagonized by MIP-1 beta), whose production or release by adherent marrow cells is inducible by AcSDKP. Such a mechanism may offer a method for obtaining localized increases in vivo of cytokines like MIP-1 alpha, suggesting novel and perhaps less toxic strategies for protecting primitive normal progenitors during repeated treatments with cycle-active chemotherapeutic agents where escalating the dose of drug given would be desirable.
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PMID:The tetrapeptide AcSDKP specifically blocks the cycling of primitive normal but not leukemic progenitors in long-term culture: evidence for an indirect mechanism. 806 44

Macrophage inflammatory protein-alpha (MIP-1 alpha), an 8-kDa peptide produced by stimulated macrophages, has been recently sequenced and cloned. In addition to its inflammatory effects, MIP-1 alpha inhibits proliferation of immature hematopoietic progenitors both in vitro and in vivo. Because the gene coding for MIP-1 alpha is expressed in peripheral blood cells obtained from patients with acute myelogenous leukemia (AML), we sought to evaluate the effect of MIP-1 alpha on AML precursors. We studied bone marrow samples from 21 AML patients using both the AML blast colony assay and the delta suspension culture assay. We found that recombinant human (rh) MIP-1 alpha significantly inhibits early and mature AML progenitors with sample-to-sample variability, by up to 79% at concentrations ranging from 40 to 1600 ng/ml. These results were obtained in the presence of fetal calf serum either alone or with granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, or interleukin-3. In contrast, rhMIP-1 alpha (400 ng/ml) did not significantly affect normal colony-forming unit granulocyte-macrophage (CFU-GM), or burst-forming unit-erythroid (BFU-E) proliferation. These data prompted us to delineate the inhibitory mechanism of MIP-1 alpha. Consequently, we used the thymidine suicide technique to measure DNA synthesis in AML progenitors and the enzyme-linked immunosorbent assay to quantify intracellular levels of interleukin-1 beta in AML blasts following incubation with MIP-1 alpha. We found that whereas MIP-1 alpha prevented AML progenitors from entering the proliferative phase of the cell cycle, it had no effect on interleukin-1 beta levels. Taken together, our data suggest that MIP-1 alpha may have clinical benefits in therapy for AML and should be considered for evaluation in a clinical setting.
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PMID:Inhibition of acute myelogenous leukemia progenitor proliferation by macrophage inflammatory protein 1-alpha. 818 37

A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst-forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP-1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.
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PMID:Use of 5-fluorouracil to analyze the effect of macrophage inflammatory protein-1 alpha on long-term reconstituting stem cells in vivo. 845 96

Macrophage-stimulating protein (MSP), originally identified as an inducer of murine resident macrophage responsiveness to chemoattractants, is a ligand for human RON/murine STK receptor protein tyrosine kinases. Since STK was cloned from populations enriched for hematopoietic stem cells, we initiated studies on the effects of MSP on colony formation by granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) myeloid progenitor cells. MSP alone had no colony stimulating activity. However, MSP caused about a 50% suppression of CFU-GM colony formation induced by synergistic combinations of SLF or Flt-L plus GM-CSF, G-CSF, or IL-3 and of BFU-E and CFU-GEMM colonies induced by SLF or Flt3-L plus Epo or Epo and IL-3. In contrast, MSP had no effect on progenitors stimulated by one growth factor. MSP also suppressed colony formation by stimulated cord blood progenitors, but only after preinduction to a rapidly cycling state. It was previously reported that several members of the chemokine family synergistically suppress myeloid progenitor proliferation. Likewise, synergistic suppression was observed when MSP was paired with VEGF, MIP-1 alpha, IL-8, PF4, MCP-1, IP-10, or ENA-78, or when VEGF was paired with the chemokines; and the required MSP concentration was more than 100-fold less than for MSP alone. Additionally, MSP or VEGF inhibited proliferation of the human myeloid growth factor-dependent cell line, M07e, but a sustained effect required multiple additions over time. At the least, some of the MSP suppressive effects on myeloid progenitors, as assessed on single isolated CD34 marrow cells, appeared to be directly on the progenitors; sustained additions of MSP were required to see this effect. The suppressive action of MSP and its synergism with proteins of the chemokine family may be of relevance to regulation of blood cell production.
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PMID:Macrophage-stimulating protein, a ligand for the RON receptor protein tyrosine kinase, suppresses myeloid progenitor cell proliferation and synergizes with vascular endothelial cell growth factor and members of the chemokine family. 869 17


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