CHEMOKINE REGULATION OF HUMAN MEGAKARYOCYTOPOIESIS
CHEMOKINE REGULATION OF HUMAN MEGAKARYOCYTOPOIESIS
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DOI：
10.1182/blood.v86.7.2559.bloodjournal8672559
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发表时间：
1995-10-01
期刊：
影响因子：
20.3
通讯作者：
PONCZ, M
中科院分区：
文献类型：
--
作者：
GEWIRTZ, AM;ZHANG, J;PONCZ, M
我们以前已经证明，血小板因子4（PF 4），血小板特异性CXC趋化因子，可以直接和特异性抑制人巨核细胞集落形成。因此，我们假设PF 4可能作为一个负的巨核细胞生成的自分泌调节剂。在这里，我们提出了额外的研究特征的CXC趋化因子对人类巨核细胞发育的抑制作用。我们首先证实了我们的初步研究表明，重组人（rH）PF 4，像天然蛋白质，抑制巨核细胞生成。然后，我们研究了其他CXC家族成员的抑制特性。神经元活化肽-2（NAP-2）是一种天然存在的N-末端切割的β TG肽，被发现能抑制巨核细胞生成，其效力比PF 4高2至3个数量级。结构功能研究表明，N-末端突变消除了NAP-2的中性粒细胞激活特性（NAP-2（E2->A）），也消除了其抑制巨核细胞发育的能力。进一步的研究表明，这种类型的嵌合PF 4蛋白（AELR/PF 4），其中PF 4的N-末端被替换为NAP-2的前四个氨基酸也是一种有效的巨核细胞生成抑制剂。白细胞介素（IL）-8，另一种CXC趋化因子和三种CC趋化因子（巨噬细胞抑制蛋白-1 α [MIP-1 α]，MIP-1 β和C10）也在NAP-2等效剂量下特异性抑制巨核细胞集落形成。CXC和CC趋化因子抑制是相加的，表明该作用可能通过共同的途径介导。NAP-2和MIP-1 α的抑制作用不能通过向培养物中加入生理相关量的重组人巨核细胞生长和发育因子（MGDR）（50 ng/mL）来克服。使用北方印迹和逆转录-聚合酶链反应（RT-PCR）为基础的分析，我们记录了总血小板RNA和正常人巨核细胞中IL-8受体亚型α和β的mRNA表达。基于这些结果，我们推测趋化因子在调节巨核细胞生成中起生理作用。由于趋化因子是由辅助骨髓细胞，自分泌和旁分泌的生长控制建议，其影响可能会发挥，部分，通过α和β IL-8受体。(C)1995年，美国血液学会。
We have previously shown that platelet factor 4 (PF4), a platelet-specific CXC chemokine, can directly and specifically inhibit human megakaryocyte colony formation. We therefore hypothesized that PF4 might function as a negative autocrine regulator of megakaryocytopoiesis. Herein we present additional studies characterizing the inhibitory effect of CXC chemokines on human megakaryocyte development. We first corroborated our initial studies by showing that recombinant human (rH) PF4, like the native protein, inhibited megakaryocytopoiesis. We then examined the inhibitory properties of other CXC family members. Neutrophil activating peptide-2 (NAP-2), a naturally occurring N-terminally cleaved beta TG peptide, was found to inhibit megakaryocytopoiesis with two to three orders of magnitude greater potency than PF4. Structure function studies showed that an N-terminal mutation, which eliminated NAP-2's neutrophil activating properties (NAP-2(E2-->A)), also abrogated its ability to inhibit megakaryocyte development. Further investigations of this type demonstrated that a chimeric PF4 protein (AELR/PF4) in which PF4's N-terminus was replaced with the first four amino acids of NAP-2 was also a potent inhibitor of megakaryocytopoiesis. Interleukin (IL)-8, another CXC chemokine, and three CC chemokines (macrophage inhibitory protein-1 alpha [MIP-1 alpha], MIP-1 beta, and C10) also specifically inhibited megakaryocyte colony formation at NAP-2 equivalent doses. CXC and CC chemokine inhibition was additive suggesting that the effects might be mediated through a common pathway. The inhibitory effects of NAP-2 and MIP-1 alpha could not be overcome by adding physiologically relevant amounts of recombinant human megakaryocyte growth and development factor (MGDR) (50 ng/mL) to the cultures. Using Northern blot and reverse transcriptase-polymerase chain reaction (RT-PCR) based analyses, we documented mRNA expression of IL-8 receptor isoforms alpha and beta in total platelet RNA and in normal human megakaryocytes, respectively. Based on these results, we hypothesize that chemokines play a physiologic role in regulating megakaryocytopoiesis. Because chemokines are elaborated by ancillary marrow cells, both autocrine and paracrine growth control is suggested, the effects of which might be exerted, in part, through alpha and beta IL-8 receptors. (C) 1995 by The American Society of Hematology.