Abstract
Objective: Abdominal aortic aneurysm (AAA) is a complex and fatal vascular disease for which specific treatments are still lacking. This study explored the effect and possible mechanisms of prenyl diphosphate synthase subunit 2 (PDSS2) on angiotensin II (Ang II)-induced AAA in human vascular smooth muscle cells (VSMCs). Material and methods: The AAA cell model was established by treating VSMCs with 1 μM Ang II for 24 h. The effect of Ang II on VSMC viability was detected by cell counting kit-8 assay. The role of PDSS2 on VSMC proliferation was examined using the 5-ethynyl-2'-deoxyuridine method. The influence of Ang II and PDSS2 on VSMC apoptosis was analyzed by flow cytometry. The expression changes of PDSS2, apoptosis-related proteins, and phosphatidylinositol 3 kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway-related proteins were detected by Western blot analysis. Results: After treatment with Ang II, the VSMCs showed decreased viability and increased apoptosis (P < 0.01). PDSS2 expression was low in the AAA tissues and Ang II-treated VSMCs (P < 0.01). PDSS2 promoted the proliferation and blocked the apoptosis of Ang II-treated VSMCs, and si-PDSS2 showed the opposite effect (P < 0.01). PDSS2 also decreased the levels of p-mTOR, p-AKT, and p-PI3K, which, in turn, were increased by si-PDSS2 (P < 0.01). Conclusion: PDSS2 was downregulated in AAA and retarded the progression of VSMCs partially through the PI3K/AKT/mTOR pathway. This work explored the molecular mechanism of PDSS2 in the prevention, diagnosis, and treatment of AAA.