The Effect of Rapamycin on the Transformation of Rat Vascular Adventitial Cells Induced by High Phosphorus into Osteoblast-like Cells Based on the mTOR Pathway
FAN Xiaorong
ZHANG Xusheng
TAN Xiaoqing
PENG Jun
Abstract：Objective: To investigate the effect of rapamycin on the phenotypic transformation of rat vascular adventitial cells into osteoblast-like cells induced by high phosphate, based on the mammalian target of rapamycin (mTOR) pathway. Methods: Primary rat vascular adventitial fibroblasts were isolated. A calcification medium (high glucose DMEM + 10% fetal bovine serum + 10 mmol/L beta-glycerophosphate + 0.05 mmol/L ascorbic acid + 100 mmol/L dexamethasone) was used to induce a calcification model in rat vascular adventitial cells. The calcium content within the cells, alkaline phosphatase (ALP) activity, and calcium nodules observed by alizarin red staining were used to evaluate the degree of cell calcification. Real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot were used to detect the mRNA and protein expression levels of osteogenic-related molecules, including core binding factor alpha 1 (Cbfα1), bone morphogenetic protein 2 (BMP2), and key proteins in the mTOR pathway, such as phosphorylated mTOR (p-mTOR). Results: Compared with the control group, the intracellular calcium content and ALP activity were significantly increased in the model group (P < 0.05). Alizarin red staining showed that the model group had numerous orange-red calcified nodules, while the control group had none. RT-qPCR and Western blot results showed that compared with the control group, the mRNA and protein expression levels of Cbfα1 and BMP2 were upregulated in the model group (P < 0.05), and p-mTOR protein expression was also increased (P < 0.05). Compared with the model group, both the high- and low-dose rapamycin groups showed downregulation of Cbfα1 and BMP2 mRNA expression, and decreased protein expression of Cbfα1, BMP2, and p-mTOR (P < 0.05), with a dose-dependent effect. Alizarin red staining showed that the size and number of calcium nodules in the high- and low-dose rapamycin groups were reduced compared to the model group. Conclusion: Rapamycin can inhibit the phenotypic transformation of rat vascular adventitial cells into osteoblast-like cells induced by high phosphate, reduce cellular calcification, and its mechanism may be related to the inhibition of the mTOR pathway.
Keywords：mammalian target of rapamycin proteinvascular adventitial cellsrapamycincore tuberculin factor α1bone morphogenetic protein 2experimental study
Publication Date：2025-10-10
Online Publishing Date：2025-10-24(First online date of this platform, not the publication date of the document)
Pages：6( 2949-2954 )