Wang Yimeng, Sun Luguo, Song Zhenbo, Wang Danfeng, Bao Yongli, Li Yuxin
National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun 130024, China; Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun 130024, China.
Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun 130024, China.
Mol Immunol. 2017 Feb;82:94-103. doi: 10.1016/j.molimm.2016.12.021. Epub 2017 Jan 5.
Maspin (mammary serine protease inhibitor) is a non-inhibitory member of the serine protease inhibitor superfamily and a tumor suppressor in several cancers due to its ability to inhibit cell invasion, angiogenesis, and promote apoptosis. However, its immunomodulatory function remains largely unexplored. Thus, we explored the potential link between Maspin and macrophage function, first evaluating the regulatory effects of conditioned medium (CM) of a Maspin-overexpressing CHO cell strain on mouse peritoneal macrophage phagocytosis and cytokine secretion. Next, we used a transwell co-culture system and recombinant Maspin (rMaspin) to confirm the effects of Maspin on macrophages, and attempted to clarify the underlying mechanisms. We found that irrespective of CM, rMaspin or co-culture of Maspin-overexpressing cells with macrophages impaired macrophages phagocytosing Saccharomyces cerevisiae. Furthermore, q-RT-PCR or ELISA confirmed increased IL-1β, TNF-α, IFN-γ, IL-6, IL-12, IL-10, and M1 marker iNOS production in macrophages after Maspin stimulation, but TGF-β and M2 marker Arg-1 production were suppressed. Western blot showed activated NF-κB signaling in Maspin-stimulated macrophages; upregulated cytokines were lowered, and impaired phagocytosis recovered after blocking NF-κB signaling with PDTC. Thus, Maspin mildly inhibited phagocytic activity, but markedly enhanced inflammatory cytokine production and likely skewed macrophages towards M1 polarization, partially due to activation of NF-κB signaling. These results reveal a novel biological function of Maspin in modulating macrophage activity and may open a new avenue for Maspin-based tumor therapy.
Maspin（乳腺丝氨酸蛋白酶抑制剂）是丝氨酸蛋白酶抑制剂超家族的一个非抑制性成员，由于其具有抑制细胞侵袭、血管生成以及促进细胞凋亡的能力，在多种癌症中发挥肿瘤抑制作用。然而，其免疫调节功能在很大程度上仍未得到充分探索。因此，我们探究了Maspin与巨噬细胞功能之间的潜在联系，首先评估了过表达Maspin的CHO细胞系条件培养基（CM）对小鼠腹腔巨噬细胞吞噬作用和细胞因子分泌的调节作用。接下来，我们使用Transwell共培养系统和重组Maspin（rMaspin）来证实Maspin对巨噬细胞的影响，并试图阐明其潜在机制。我们发现，无论CM、rMaspin还是过表达Maspin的细胞与巨噬细胞共培养，都会损害巨噬细胞吞噬酿酒酵母的能力。此外，q-RT-PCR或ELISA证实，Maspin刺激后巨噬细胞中白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、干扰素-γ（IFN-γ）、白细胞介素-6（IL-6）、白细胞介素-12（IL-12）、白细胞介素-10（IL-10）以及M1标志物诱导型一氧化氮合酶（iNOS）的产生增加，但转化生长因子-β（TGF-β）和M2标志物精氨酸酶-1（Arg-1）的产生受到抑制。蛋白质印迹法显示，Maspin刺激的巨噬细胞中核因子-κB（NF-κB）信号通路被激活；在用吡咯烷二硫代氨基甲酸盐（PDTC）阻断NF-κB信号通路后，上调的细胞因子水平降低，受损的吞噬作用得以恢复。因此，Maspin轻度抑制吞噬活性，但显著增强炎性细胞因子的产生，并可能使巨噬细胞倾向于M1极化，部分原因是NF-κB信号通路的激活。这些结果揭示了Maspin在调节巨噬细胞活性方面的一种新的生物学功能，并可能为基于Maspin的肿瘤治疗开辟一条新途径。
