Porphyromonas gingivalis hijacks mitophagy and lysosomal function to persist in endothelial cells

Cheng Zheng¹Jianmin Huang¹Shengming Xu¹Bin Lu¹Hanxin Que¹Tianhao Chen¹Yubo Hou¹Linlin He¹Xia Fan¹Fa-Ming Chen^2*Yi Wang^1*Hui Deng^1*

• ¹Wenzhou Medical University, Wenzhou, China
• ²School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi Province, China

The direct infection of endothelial cells by Porphyromonas gingivalis (P. gingivalis), a keystone periodontal pathogen, has been implicated in the development of atherosclerosis. While non-selective autophagy facilitates its intracellular persistence in endothelial cells, the role of selective autophagy in this process remains unclear. Here, we investigated whether P. gingivalis evades clearance by hijacking mitophagy and lysosomes, thereby promoting its intracellular survival in endothelial cells. Our findings demonstrated that P. gingivalis initiates PTEN-induced putative kinase 1 (PINK1)-Parkin-mediated mitophagy in human aortic endothelial cells (HAECs), leading to increased formation of autophagosomes and mitophagosomes, but disrupted autophagy/mitophagy flux. This blockage of autophagy/mitophagy flux was linked to lysosomal dysfunction, characterized by increased lysosome number, lysosomal membrane permeabilization, disruption of the lysosomal acidic environment, and decreased enzymatic activity. Additionally, antibiotic protection assays and SYTO-9 staining further revealed that P. gingivalis promotes its intracellular survival in endothelial cells by initiating mitophagy and impairing lysosomal function. Furthermore, the mitophagy activator decreased the colocalization of P. gingivalis with microtubule-associated protein 1 light chain 3 (LC3)-p62, LC3-NDP52, and lysosomal-associated membrane protein 1 (LAMP1), suggesting that P. gingivalisinitiated mitophagy inhibited xenophagosome formation and autophagosome/xenophagosomelysosome fusion. Collectively, P. gingivalis may promote its intracellular survival in endothelial cells by initiating PINK1-Parkin-mediated mitophagy and impairing lysosomal function, thereby suppressing xenophagosome formation and xenophagic degradation. This study provides new insights into the mechanisms by which P. gingivalis persists in endothelial cells and its potential role in atherosclerosis progression.