Department of Cardiology, The First Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang, 110001, Liaoning Province, People Republic of China.
College of Basic Medical Science, Institute of Translational Medicine, Key Laboratory of Medical Cell Biology, Ministry of Education, Key Laboratory of Liaoning Province, China Medical University, Shenyang, 110122, Liaoning Province, People Republic of China.
Int J Biol Sci. 2022 Jan 1;18(1):409-425. doi: 10.7150/ijbs.65030. eCollection 2022.
DNA polymerase gamma (PolG) is the major polymerase of mitochondrial DNA (mtDNA) and essential for stabilizing mitochondrial function. Vascular calcification (VC) is common senescence related degenerative pathology phenomenon in the end-stage of multiple chronic diseases. Mitochondrial dysfunction was often observed in calcified vessels, but the function and mechanism of PolG in the calcification process was still unknown. The present study found PolG mice presented more severe calcification of aortas than wild type (WT) mice with vitamin D3 (Vit D3) treatment, and this phenomenon was also confirmed . Mechanistically, PolG could enhance the recruitment and interaction of p53 in calcification condition to recover mitochondrial function and eventually to resist calcification. Meanwhile, we found the mutant PolG (D257A) failed to achieve the same rescue effects, suggesting the 3'-5' exonuclease activity guarantee the enhanced interaction of p53 and PolG in response to calcification stimulation. Thus, we believed that it was PolG, not mutant PolG, could maintain mitochondrial function and attenuate calcification and . And PolG could be a novel potential therapeutic target against calcification, providing a novel insight to clinical treatment.
DNA 聚合酶 γ(PolG)是线粒体 DNA(mtDNA)的主要聚合酶,对稳定线粒体功能至关重要。血管钙化(VC)是多种慢性疾病终末期常见的衰老相关退行性病理现象。钙化血管中常观察到线粒体功能障碍,但 PolG 在钙化过程中的功能和机制尚不清楚。本研究发现,维生素 D3(Vit D3)处理后,PolG 基因敲除小鼠的主动脉钙化比野生型(WT)小鼠更严重,这一现象也得到了证实。从机制上讲,PolG 可以增强 p53 在钙化条件下的募集和相互作用,从而恢复线粒体功能,最终抵抗钙化。同时,我们发现突变型 PolG(D257A)未能达到相同的挽救效果,这表明 3'-5'外切酶活性保证了 p53 和 PolG 之间在应对钙化刺激时的增强相互作用。因此,我们认为是 PolG 而不是突变型 PolG 维持了线粒体功能并减轻了钙化。PolG 可能是一种针对钙化的新型潜在治疗靶点,为临床治疗提供了新的思路。