Platelet-derived growth factor receptor β activation and regulation in murine myelofibrosis
Platelet-derived growth factor receptor β activation and regulation in murine myelofibrosis
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DOI：
10.3324/haematol.2019.226332
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发表时间：
2020-08-01
期刊：
影响因子：
10.1
通讯作者：
Kappert, Kai
中科院分区：
文献类型：
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作者：
Kramer, Frederike;Dernedde, Jens;Kappert, Kai
血小板源性生长因子（PDGF）及其受体在原发性骨髓纤维化中起决定性作用。虽然PDGF受体β（PDGFR β）表达在与骨髓纤维化分级相关的患者的骨髓基质细胞中增加，但关于PDGFR β信号传导在骨髓纤维化中的确切作用的知识很少。使用骨髓纤维化的加塔-1（低）小鼠模型，我们应用RNA测序、蛋白质表达分析、多光谱成像以及作为骨髓组织中的新方法的原位邻位连接测定来提供骨髓纤维化发展期间PDGFR β信号传导和调节的详细表征。我们观察到明显纤维化骨髓中PDGFR β和PDGF-B蛋白表达的增加，沿着PDGFR β-PDGF-B相互作用的增加，通过邻位连接分析。然而，PDGFR β酪氨酸磷酸化水平没有增加。因此，我们专注于调节PDGFR β的蛋白酪氨酸磷酸酶作为内源性PDGFR β拮抗剂。基因表达分析显示PDGFR β靶向磷酸酶之间的不同表达动力学。特别是，我们观察到增强的T细胞蛋白酪氨酸磷酸酶蛋白表达和PDGFR β-T细胞蛋白酪氨酸磷酸酶的相互作用，在早期和明显的纤维化骨髓的加塔-1（低）-小鼠。在体外，T细胞蛋白酪氨酸磷酸酶（Ptpn 2）敲低增加了Y-751和Y-1021处的PDGFR β磷酸化，导致成纤维细胞中下游信号传导增强。此外，Ptpn 2敲低细胞显示出增加的生长速率时，暴露于低血清生长培养基。总之，PDGF信号传导在骨髓纤维化期间受到差异调节。蛋白酪氨酸磷酸酶，迄今尚未被检查在疾病的进展，是新的和迄今未被认识的组成部分，在骨髓纤维化。
Tere is prevailing evidence to suggest a decisive role for platelet- derived growth factors (PDGF) and their receptors in primary myelofibrosis. While PDGF receptor beta (PDGFR beta) expression is increased in bone marrow stromal cells of patients correlating with the grade of myelofibrosis, knowledge on the precise role of PDGFR beta signaling in myelofibrosis is sparse. Using the Gata-1(low) mouse model for myelofibrosis, we applied RNA sequencing, protein expression analyses, multispectral imaging and, as a novel approach in bone marrow tissue, an in situ proximity ligation assay to provide a detailed characterization of PDGFR beta signaling and regulation during development of myelofibrosis. We observed an increase in PDGFR beta and PDGF-B protein expression in overt fibrotic bone marrow, along with an increase in PDGFR beta-PDGF-B interaction, analyzed by proximity ligation assay. However, PDGFR beta tyrosine phosphorylation levels were not increased. We therefore focused on regulation of PDGFR beta by protein tyrosine phosphatases as endogenous PDGFR beta antagonists. Gene expression analyses showed distinct expression dynamics among PDGFR beta-targeting phosphatases. In particular, we observed enhanced T-cell protein tyrosine phosphatase protein expression and PDGFR beta-T-cell protein tyrosine phosphatase interaction in early and overt fibrotic bone marrow of Gata-1(low)- mice. in vitro, T-cell protein tyrosine phosphatase (Ptpn2) knockdown increased PDGFR beta phosphorylation at Y-751 and Y-1021, leading to enhanced downstream signaling in fibroblasts. Furthermore, Ptpn2 knockdown cells showed increased growth rates when exposed to low-serum growth medium. Taken together, PDGF signaling is differentially regulated during myelofibrosis. Protein tyrosine phosphatases, which have so far not been examined during disease progression, are novel and hitherto unrecognized components in myelofibrosis.