基于“土爰稼穑”探索健脾补土法修复干细胞“土壤”ECM的紊乱阻遏胃癌前病变的分子机制

Extracellular matrix (ECM), which serves as the “soil” for stem cells, can accommodate, support, nourish and protect stem cells, and thus determines the fate of stem cells. These characteristics of ECM are similar to the TCM theory of “tu yuan jia se”. Previously, our studies have proven that Jianpibutu formula Weipixiao was clinically effective in treating gastric precancerous lesions (GPL), and we also found that Weipixiao could markedly attenuate GPL by repressing Lgr5+ gastric stem cells' abnormal migration and over-proliferation. However, the underlying mechanisms of this effect still remain unclear. Inspired by the TCM theory of “tu yuan jia se”and a new research finding showing that ECM homeostasis, which mainly regulated by YAP/TEAD and then determine biological responses of Lgr5+ gastric stem cells. We speculate that Jianpibutu method attenuates GPL by improving YAP/TEAD-mediated ECM and thereby inhibiting abnormal migration, differentiation, proliferation and apoptosis of Lgr5+ gastric stem cells. Our team will use the classic GPL rat model to investigate: 1) the alteration of ECM “soil” and the consequential aberrant status of Lgr5+ gastric stem cells after Jianpibutu treating. 2) How does Jianpibutu method improve ECM “soil” through YAP/TEAD mediation? We expect our study will enrich the scientific connotation of “tu yuan jia se”, and provide the scientific evidence for Jianpibutu method in GPL therapy.

细胞外基质（ECM）是干细胞赖以生存的“土壤”，决定干细胞的命运，对干细胞有容纳、支撑、营养及保护作用，这与中医藏象“土爰稼穑”相契合。临床证实，健脾补土法代表方胃痞消治疗胃癌前病变（GPL）疗效确切。前期发现，胃痞消可明显抑制Lgr5+胃干细胞离巢和过度增殖阻遏GPL。但其通过何种途径实现此效应尚不清楚。受启发于土爰稼穑，结合最新研究成果—胃干细胞“种子”命运主要受YAP/TEAD介导的ECM“土壤”调控。我们假设：健脾补土法通过修复YAP/TEAD介导的ECM（土壤）紊乱，抑制Lgr5+胃干细胞（种子）的迁移、分化、增殖与凋亡异常阻遏癌变。本项目拟用经典GPL大鼠模型探索：①健脾补土法干预后ECM“土壤”变化及对Lgr5+胃干细胞“种子”异常状态的影响；②健脾补土法如何调控YAP/TEAD改善ECM“土壤”的分子机制。丰富“土爰稼穑”的科学内涵，为健脾补土法干预GPL提供科学依据。

胃癌前病变（GPL）属难治性疾病且极易癌变，严重影响患者的生活质量。细胞外基质（ECM）是干细胞赖以生存的“土壤”，能够对干细胞起容纳、支撑、营养及保护作用，是引发GPL的关键致病因素。本项目验证的科学假说为：健脾补土法通过修复YAP/TEAD介导的ECM紊乱，抑制Lgr5+胃干细胞的迁移、分化、增殖与凋亡异常阻遏癌变。通过构建MNNG诱导的GPL大鼠模型，观察健脾补土法对GPL大鼠病理组织、ECM结构的治疗作用，检测健脾补土法干预后ECM微环境组分及相关因子的差异蛋白表达谱以及Lgr5+胃干细胞生物学行为，并分析YAP磷酸化/去磷酸化、YAP/TEAD信号活化/抑制。研究结果显示：健脾补土法能够改善GPL大鼠胃黏膜肠化生及部分异型增生等病理学改变，缓解胃黏膜上皮的ECM基质胶原纤维增加、胶原沉积现象，透射电镜下可见胃黏膜上皮ECM结构显著好转。通过蛋白芯片和微阵列分析技术，发现健脾补土法可显著下调ECM相关分子FGF-BP、beta-catenin、ICAM-1/CD54、FSTL的表达。健脾补土法能够抑制Lgr5+胃干细胞恶性生物学行为，并能调控干性标志物Sox2、Oct4的表型变化；健脾补土法干预后GPL大鼠的p-YAP表达水平显著升高，而YAP的蛋白表达水平显著降低，同时YAP/TEAD结合显著下降，说明YAP/TEAD活化状态得到抑制。健脾补土法治疗GPL的潜在药效机制主要涉及YAP/TEAD信号，健脾补土法可通过抑制YAP/TEAD活化状态改善胃黏膜上皮的ECM微环境，抑制Lgr5+胃干细胞恶性行为阻遏癌变。本项目探讨了健脾补土法治疗GPL的药效机制，丰富了中医药治疗胃癌前病变的科学内涵，为临床推广应用提供新的理论依据。