Department of Immunology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Immunology of Infectious Diseases Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
J Cell Mol Med. 2022 Nov;26(22):5647-5656. doi: 10.1111/jcmm.17594. Epub 2022 Oct 19.
The human dental pulp stem cells (hDPSCs) are one of the readily available sources of multipotent mesenchymal stem cells (MSCs) and can be considered as a type of tool cells for cell-based therapies. However, the main limitation in the clinical use of these cells is DPSC senescence, which can be induced by lipopolysaccharide (LPS) of oral pathogenic bacteria. Up to now, far little attention has been paid to exploring the molecular mechanisms of senescence in DPSCs. So, the current study aimed to investigate the underlying molecular mechanism of senescence in hDPSCs stimulated with Porphyromonas gingivalis (P. gingivalis) and Escherichia coli (E. coli)-derived LPSs, by evaluating both mRNA and protein expression of four important senescence-related genes, including TP53, CDKN1A, CDKN2A and SIRT1. To this purpose, hDPSCs were stimulated with different LPSs for 6, 24 and 48 h and then the gene expression was evaluated using quantitative real-time polymerase chain reaction (qPCR) and western blotting. Following stimulation with P. gingivalis and E. coli-derived LPSs, the relative mRNA and protein expression of all genes were significantly up-regulated in a time-dependent manner, as compared with unstimulated hDPSCs. Moreover, the hDPSCs stimulated with P. gingivalis LPS for 6 and 24 h had the highest mRNA expression of CDKN1A and SIRT1, respectively (p < 0.0001), whereas the highest mRNA expression of CDKN2A and TP53 was seen in hDPSCs stimulated with E. coli LPS for 48 h (p < 0.0001). In summary, because DPSCs have been reported to have therapeutic potential for several cell-based therapies, targeting molecular mechanisms aiming at preventing DPSC senescence could be considered a valuable strategy.
牙髓干细胞（hDPSCs）是多能间充质干细胞（MSCs）的一种易于获得的来源，可以被视为细胞疗法的一种工具细胞。然而，这些细胞在临床应用中的主要限制是 DPSCs 的衰老，这可以被口腔致病菌的脂多糖（LPS）诱导。到目前为止，对于探索 DPSCs 衰老的分子机制，人们关注甚少。因此，本研究旨在通过评估四个重要的衰老相关基因（TP53、CDKN1A、CDKN2A 和 SIRT1）的 mRNA 和蛋白质表达，来研究 hDPSCs 受牙龈卟啉单胞菌（P. gingivalis）和大肠杆菌（E. coli）衍生 LPS 刺激后衰老的潜在分子机制。为此，用不同的 LPS 刺激 hDPSCs 6、24 和 48 小时，然后用实时定量聚合酶链反应（qPCR）和蛋白质印迹法评估基因表达。与未刺激的 hDPSCs 相比，用 P. gingivalis 和 E. coli 衍生 LPS 刺激后，所有基因的相对 mRNA 和蛋白质表达均呈时间依赖性显著上调。此外，用 P. gingivalis LPS 刺激 6 和 24 小时的 hDPSCs 分别具有最高的 CDKN1A 和 SIRT1 mRNA 表达（p < 0.0001），而用 E. coli LPS 刺激 48 小时的 hDPSCs 具有最高的 CDKN2A 和 TP53 mRNA 表达（p < 0.0001）。总之，由于已经报道 DPSCs 对几种基于细胞的疗法具有治疗潜力，因此靶向旨在预防 DPSC 衰老的分子机制可以被视为一种有价值的策略。
