CLEC-2 stimulates IGF-1 secretion from podoplanin-positive stromal cells and positively regulates erythropoiesis in mice
CLEC-2 stimulates IGF-1 secretion from podoplanin-positive stromal cells and positively regulates erythropoiesis in mice
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DOI：
10.1111/jth.15317
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发表时间：
2021-04-20
影响因子：
10.4
通讯作者：
Suzuki-Inoue, Katsue
中科院分区：
文献类型：
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作者：
Otake, Shimon;Sasaki, Tomoyuki;Suzuki-Inoue, Katsue
背景红细胞生成是一个复杂的多步骤过程，红细胞的生成是一个复杂的过程。C型凝集素样受体2(CLEC-2)是一种PDPN受体，几乎仅表达于血小板和巨核细胞表面。据报道，巨核细胞/血小板CLEC-2缺失会导致小鼠贫血和血小板减少。骨髓(BM)中表达PDPN的基质细胞也被报道通过CLEC-2/PDPN的相互作用促进巨核细胞的扩张和成熟。目的研究巨核细胞/血小板中CLEC-2的特异性缺失是如何导致贫血的。用细胞因子阵列和ELISA法分析CLEC-2刺激的表达PDPN的基质细胞条件培养液，并与未成熟红细胞共培养。结果巨核细胞/血小板特异性CLEC-2条件性基因敲除(Clec1b(Delta PLT))小鼠骨髓红系细胞凋亡率增加。此外，骨髓中表达PDPN的基质细胞依赖于CLEC-2/PDPN的相互作用而分泌胰岛素样生长因子1(IGF-1)。IGF-1受体抑制剂预处理可增加体外培养的红细胞凋亡率，抑制其增殖。此外，Clec1b(Delta PLT)小鼠血清和骨髓细胞外液中的IGF-1浓度降低，Clec1b(Delta PLT)小鼠的IGF-1替代可减轻贫血。结论CLEC-2刺激表达PDPN的基质细胞分泌IGF-1对红细胞有正向调节作用。这种新的红细胞生成调控机制表明，由巨核细胞和表达PDPN的基质细胞组成的微环境支持红细胞生成。
Background Erythropoiesis is a complex multistep process by which erythrocytes are produced. C-type lectin-like receptor 2 (CLEC-2) is a podoplanin (PDPN) receptor almost exclusively expressed on the surface of platelets and megakaryocytes. Deletion of megakaryocyte/platelet CLEC-2 was reported to cause anemia along with thrombocytopenia in mice. PDPN-expressing stromal cells in the bone marrow (BM) were also reported to facilitate megakaryocyte expansion and maturation depending on the CLEC-2/PDPN interaction.Objectives We investigated how specific deletion of CLEC-2 in megakaryocytes/platelets leads to anemia.Methods We used flow cytometry to analyze maturation of erythroblasts, apoptotic cell death, and cell cycle distribution. CLEC-2 stimulated PDPN-expressing stromal cell-conditioned medium was analyzed by cytokine array and ELISA, and co-cultured with immature erythroblasts. Cytokine levels in serum and BM extracellular fluid were quantified by ELISA.Results We observed increased apoptosis of BM erythroblasts in megakaryocyte/platelet-specific CLEC-2 conditional knockout (Clec1b(Delta PLT)) mice. Moreover, PDPN-expressing stromal cells in the BM secreted insulin-like growth factor 1 (IGF-1) depending on the CLEC-2/PDPN interaction. Pretreatment with IGF-1 receptor inhibitor increased apoptosis rate and decreased the proliferation of erythroblasts in vitro. Furthermore, in Clec1b(Delta PLT) mice, IGF-1 concentrations in serum and BM extracellular fluid were decreased, and IGF-1 replacement in Clec1b(Delta PLT) mice attenuated anemia.Conclusions Our findings suggest that IGF-1 secretion from PDPN-expressing stromal cells by CLEC-2 stimulation positively regulates erythroblasts. This novel mechanism of erythropoiesis regulation indicates that a microenvironment consisting of megakaryocytes and PDPN-expressing stromal cells supports erythropoiesis.