Jeong Jinseon, Kim Yong-Jae, Lee Do Young, Moon Byoung-Gon, Sohn Ki-Young, Yoon Sun Young, Kim Jae Wha
1Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon, 305-333 Republic of Korea.
2Department of Functional Genomics, University of Science & Technology, Daejeon, Republic of Korea.
Cell Biosci. 2019 Jan 3;9:4. doi: 10.1186/s13578-018-0266-7. eCollection 2019.
Cancer patients treated with chemotherapy often experience a rapid decline of blood neutrophils, a dose-limiting side effect called chemotherapy-induced neutropenia. This complication brings about dose reductions or cessation of chemotherapy during treatment of cancer patients because a rapid decline of neutrophil counts increases susceptibility to infection. Here, we found that 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) attenuates gemcitabine-induced neutrophil extravasation via the inhibition of neutrophil-attracting chemokine production in macrophages using in vivo and in vitro approaches. A single intraperitoneal administration of gemcitabine induced the migration of circulating neutrophils into the peritoneal cavity in normal mice, and PLAG effectively decreased neutrophil migration by inhibiting the expression of adhesion molecules, L-selectin and LFA-1. Inhibition of CXCR2 by its antagonist, reparixin, abrogated gemcitabine-induced neutrophil migration, indicating that chemokines produced by gemcitabine mainly support neutrophil activation. In vitro experiments demonstrated that PLAG inhibited NADPH oxidase 2 (NOX2)-mediated reactive oxygen species production induced by gemcitabine, which is the upstream of MIP-2 and/or CXCL8. Importantly, PLAG down-regulated gemcitabine-induced membrane translocation of the cytosolic NOX subunit, Rac1, and phosphorylation of p47phox. The activation of upstream signaling molecules of p47phox phosphorylation, phospholipase C β3 and protein kinase C, were effectively regulated by PLAG. We also demonstrated that 1-palmitoyl-2-linoleic-3-hydroxyl-rac-glycerol (PLH), the natural form of diacylglycerol, has no effects on gemcitabine-induced CXCL8 production and dHL-60 migration, suggesting that an acetyl group at the third position of the glycerol backbone may have a key role in the regulation of neutrophil activation. Altogether, this study suggests the potential of PLAG as a therapeutic strategy to modulate chemotherapy-induced neutrophil activation for cancer patients undergoing chemotherapeutic treatment.
接受化疗的癌症患者常常会出现血液中性粒细胞迅速减少的情况，这是一种被称为化疗诱导的中性粒细胞减少症的剂量限制性副作用。这种并发症会导致癌症患者在治疗期间减少化疗剂量或停止化疗，因为中性粒细胞计数的迅速下降会增加感染易感性。在此，我们发现1-棕榈酰-2-亚油酰-3-乙酰-消旋甘油（PLAG）通过体内和体外实验，利用抑制巨噬细胞中吸引中性粒细胞的趋化因子产生，减轻吉西他滨诱导的中性粒细胞渗出。单次腹腔注射吉西他滨可诱导正常小鼠循环中性粒细胞向腹腔迁移，而PLAG通过抑制黏附分子L-选择素和淋巴细胞功能相关抗原-1（LFA-1）的表达，有效减少中性粒细胞迁移。其拮抗剂瑞帕霉素抑制CXCR2可消除吉西他滨诱导的中性粒细胞迁移，表明吉西他滨产生的趋化因子主要支持中性粒细胞活化。体外实验表明，PLAG抑制吉西他滨诱导的NADPH氧化酶2（NOX2）介导的活性氧生成，这是巨噬细胞炎性蛋白-2（MIP-2）和/或CXC趋化因子配体8（CXCL8）的上游事件。重要的是，PLAG下调吉西他滨诱导的胞质NOX亚基Rac1的膜转位以及p47phox的磷酸化。PLAG有效调节p47phox磷酸化上游信号分子磷脂酶Cβ3和蛋白激酶C的活化。我们还证明，二酰甘油的天然形式1-棕榈酰-2-亚油酰-3-羟基-消旋甘油（PLH）对吉西他滨诱导的CXCL8产生和分化的人早幼粒细胞白血病细胞系（dHL-60）迁移没有影响，这表明甘油主链第三位的乙酰基可能在调节中性粒细胞活化中起关键作用。总之，本研究提示PLAG作为一种治疗策略，对于接受化疗的癌症患者调节化疗诱导的中性粒细胞活化具有潜在作用。
