Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chemokine interleukin-8 (IL-8) is a potent chemoattractant and activator of neutrophils. Upon systemic injection, IL-8 induces an immediate neutropenia followed by a rebound granulocytosis. In this report, we discuss the effects of IL-8 on the mobilization of hematopoietic stem cells. Within 20 minutes following a single intraperitoneal injection in mice, IL-8 induces the mobilization of hematopoietic progenitor cells (HPC) with colony-forming, radioprotective, and long-term lymphomyeloid resubpopulating ability. Mobilization can be specifically prevented by pretreatment with antibodies against the beta2 integrin LFA-1 (CD11a). In monkeys, IL-8 Induces the rapid release of the metalloproteinase gelatinase-B concurrent with the mobilization of HPC. The latter effect can be prevented by blocking gelatinase-B activity using specific monoclonal antibodies, suggesting the involvement of gelatinase-B as a mediator of HPC mobilization. These results are consistent with the hypothesis that neutrophils are major regulators of stem-cell mobilization through the release of metalloproteinases (MMPs) that cleave extracellular matrix molecules to which HPC are attached.
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PMID:The role of metalloproteinases and adhesion molecules in interleukin-8-induced stem-cell mobilization. 1071 55

The CXC chemokine interleukin-8 (IL-8/CXCL8) induces rapid mobilization of hematopoietic progenitor cells (HPCs). Previously we showed that mobilization could be prevented completely in mice by pretreatment with neutralizing antibodies against the beta2-integrin LFA-1 (CD11a). In addition, murine HPCs do not express LFA-1, indicating that mobilization requires a population of accessory cells. Here we show that polymorphonuclear cells (PMNs) serve as key regulators in IL-8-induced HPC mobilization. The role of PMNs was studied in mice rendered neutropenic by administration of a single injection of antineutrophil antibodies. Absolute neutropenia was observed up to 3-5 days with a rebound neutrophilia at day 7. The IL-8-induced mobilizing capacity was reduced significantly during the neutropenic phase, reappeared with recurrence of the PMNs, and was increased proportionally during the neutrophilic phase. In neutropenic mice, the IL-8-induced mobilizing capacity was restored by the infusion of purified PMNs but not by infusion of mononuclear cells. Circulating metalloproteinase gelatinase B (MMP-9) levels were detectable only in neutropenic animals treated with PMNs in combination with IL-8, showing that in vivo activated PMNs are required for the restoration of mobilization. However, IL-8-induced mobilization was not affected in MMP-9-deficient mice, indicating that MMP-9 is not indispensable for mobilization. These data demonstrate that IL-8-induced mobilization of HPCs requires the in vivo activation of circulating PMNs.
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PMID:Neutrophils are indispensable for hematopoietic stem cell mobilization induced by interleukin-8 in mice. 1198 13