STAT3信号通路在人急性单核细胞白血病细胞向树突状细胞分化中的作用及机制探讨

摘要

Objective To detect the role and mechanisms of signal transducers and activators of transcription 3(STAT3) in promoting the differentiation of human acute monocytic leukemia cells into dendritic cells (DCs). Methods Human acute monocytic leukemia cells THP-1 were randomly divided into two groups: the observation group and the control group. Cells in the observation group were induced to differentiate into DCs by granulocyte-macrophage colony stimulating factor (GM-CSF) combined with interleukin-4 (IL-4),and we used Lipopolysaccharide (LPS) to induce THP-1-derived DC maturation; cells in the control group were not treated. The cells in the two groups were collected on day 7 of culture, the morphologic features were observed under inverted microscope; DC surface marker CD11c and DC surface functional molecules (CD80,HLA-DR,and CCR7) were detected by flow cytometry; the mRNA expression of STAT3 and E2-2 was detected by q-PCR; in addition,the protein expression of STAT3 and phosphorylation (p-STAT3) was detected by Western blotting. Results The cells in the control group showed a round shape and uniform morphology. After cytokines induction, obvious morphological changes of DCs were observed. Compared with the control group,the DC surface marker CD11c and DC surface functional molecules of the observation group were higher,and both the mRNA expression levels of STAT3 and E2-2 and the protein expression levels of STAT3 and p-STAT3 increased significantly (all P < 0.05). Conclusion During the differentiation of THP-1 cells into DCs induced by GM-CSF and IL-4,STAT3 signaling pathway activates specific nuclear transcription factor E2-2,which in turn induces the differentiation of THP-1 into DCs.%目的 探讨信号转导与转录激活因子3(STAT3)信号通路在人急性单核细胞白血病细胞向树突状细胞(DC)分化中的作用与机制.方法 将人急性单核细胞白血病细胞THP-1随机分为两组,观察组以粒细胞巨噬细胞-集落刺激因子(GM-CSF)联合白细胞介素4(IL-4)诱导其向DC分化,用脂多糖(LPS)诱导THP-1来源DC成熟;对照组不做处理.培养第7天,收集两组细胞;倒置显微镜下观察细胞形态,流式细胞术检测DC表面标志性分子CD11c及DC表面功能分子(共刺激分子CD80、组织相容性抗原HLA-DR、趋化因子CCR7),q-PCR法检测STAT3及E2-2 mRNA,Western blotting法检测STAT3总蛋白及磷酸化(p-STAT3).结果 对照组细胞呈圆形,形态均匀;细胞因子诱导后观察组细胞可见明显的树突状突起,呈现DC形态学变化.与对照组比较,观察组DC表面标志性分子CD11c及DC表面功能分子均表达增加(P均<0.05),细胞STAT3、E2-2 mRNA及STAT3蛋白、p-STAT3蛋白相对表达量均增加(P均<0.05).结论 GM-CSF联合IL-4诱导THP-1细胞向DC分化过程中,STAT3信号通路活化DC分化特异性核转录因子E2-2,进而诱导THP-1向DC分化.