We found that GroEL in Porphyromonas gingivalis accelerated tumor growth and increased mortality in tumor-bearing mice; GroEL promoted proangiogenic function, which may be the reason for promoting tumor growth. To understand the regulatory mechanisms by which GroEL increases the proangiogenic function of endothelial progenitor cells (EPCs), we explored in this study. In EPCs, MTT assay, wound-healing assay, and tube formation assay were performed to analyze its activity. Western blot and immunoprecipitation were used to study the protein expression along with next-generation sequencing for miRNA expression. Finally, a murine tumorigenesis animal model was used to confirm the results of in vitro. The results indicated that thrombomodulin (TM) direct interacts with PI₃K/Akt to inhibit the activation of signaling pathways. When the expression of TM is decreased by GroEL stimulation, molecules in the PI₃K/Akt signaling axis are released and activated, resulting in increased migration and tube formation of EPCs. In addition, GroEL inhibits TM mRNA expression by activating miR-1248, miR-1291, and miR-5701. Losing the functions of miR-1248, miR-1291, and miR-5701 can effectively alleviate the GroEL-induced decrease in TM protein levels and inhibit the proangiogenic abilities of EPCs. These results were also confirmed in animal experiments. In conclusion, the intracellular domain of the TM of EPCs plays a negative regulatory role in the proangiogenic capabilities of EPCs, mainly through direct interaction between TM and PI₃K/Akt to inhibit the activation of signaling pathways. The effects of GroEL on tumor growth can be reduced by inhibiting the proangiogenic properties of EPCs through the inhibition of the expression of specific miRNAs.

中文翻译：

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牙龈卟啉单胞菌诱导的 microRNA 的 GroEL 通过下调内皮祖细胞中血栓调节蛋白的表达来加速肿瘤新生血管形成

我们发现牙龈卟啉单胞菌中的 GroEL加速了荷瘤小鼠的肿瘤生长并增加了死亡率；GroEL促进促血管生成功能，这可能是促进肿瘤生长的原因。为了了解 GroEL 增加内皮祖细胞 (EPC) 促血管生成功能的调节机制，我们在本研究中进行了探索。在EPCs中，进行MTT实验、伤口愈合实验和成管实验来分析其活性。使用蛋白质印迹和免疫沉淀来研究蛋白质表达以及 miRNA 表达的下一代测序。最后利用小鼠肿瘤发生动物模型验证了体外结果。结果表明，血栓调节蛋白（TM）直接与PI ₃ K/Akt相互作用，抑制信号通路的激活。当 GroEL 刺激降低 TM 的表达时，PI ₃ K/Akt 信号轴中的分子被释放并激活，导致 EPC 的迁移和管形成增加。此外，GroEL 通过激活 miR-1248、miR-1291 和 miR-5701 抑制 TM mRNA 表达。丧失miR-1248、miR-1291和miR-5701的功能可以有效缓解GroEL诱导的TM蛋白水平下降并抑制EPC的促血管生成能力。这些结果也在动物实验中得到了证实。总之，EPCs的TM胞内结构域对EPCs的促血管生成能力起负向调节作用，主要是通过TM与PI ₃ K/Akt的直接相互作用抑制信号通路的激活。GroEL 对肿瘤生长的影响可以通过抑制特定 miRNA 的表达来抑制 EPC 的促血管生成特性。