■牙髓干细胞(DPSC)具有间充质干细胞特征并且具有用于基于细胞的治疗的潜力。细胞扩增对于获得足够的细胞数量是必需的。然而,持续的细胞复制导致体外细胞老化,这通常伴随着DPSC的特性和活动,并可能影响DPSC的特性和活动。连续传代可能会改变对药物治疗等外部因素的敏感性。因此,本研究旨在研究在不存在或存在外部因子的情况下,体外传代对DPSC形态和活性的潜在影响.
■将人DPSC传代培养直至达到早期传代(P5),扩展通道(P10),和后期段落(P15)。评估和比较细胞的细胞和核形态,细胞粘附,增殖能力,碱性磷酸酶(ALP)活性,和基因表达在不存在或存在的外部因素。阿仑膦酸盐(ALN)药物治疗被用作外部因素。
■DPSC的连续传代逐渐失去其正常的纺锤形,细胞和核大小增加。DPSC对ALN易感。大小和形状都改变了,导致形态异常和不均匀性。长期培养和ALN干扰细胞粘附。DPSC能够增殖而与细胞传代无关,但晚期传代中的细胞增殖速率较慢。中等剂量的ALN抑制细胞生长。ALN导致早期传代ALP活性降低。相比之下,延长传代通过增加ALP活性对ALN的反应不同。与存在ALN的早期传代相比,晚期传代显示出更高的胶原蛋白,但较低的骨钙蛋白基因表达。
传代数的增加在细胞形态和活性以及对添加外部因子的反应中起关键作用。在基础科学研究和临床应用中,应考虑细胞传代的影响。
UNASSIGNED: Dental pulp stem cells (DPSCs) possess mesenchymal stem cell characteristics and have potential for cell-based therapy. Cell expansion is essential to achieve sufficient cell numbers. However, continuous cell replication causes cell aging in vitro, which usually accompanies and potentially affect DPSC characteristics and activities. Continuous passaging could alter susceptibility to external factors such as drug treatment. Therefore, this study sought to investigate potential outcome of in vitro passaging on DPSC morphology and activities in the absence or presence of external factor.
UNASSIGNED: Human DPSCs were subcultured until reaching early passages (P5), extended passages (P10), and late passages (P15). Cells were evaluated and compared for cell and nuclear morphologies, cell adhesion, proliferative capacity, alkaline phosphatase (ALP) activity, and gene expressions in the absence or presence of external factor. Alendronate (ALN) drug treatment was used as an external factor.
UNASSIGNED: Continuous passaging of DPSCs gradually lost their normal spindle shape and increased in cell and nuclear sizes. DPSCs were vulnerable to ALN. The size and shape were altered, leading to morphological abnormality and inhomogeneity. Long-term culture and ALN interfered with cell adhesion. DPSCs were able to proliferate irrespective of cell passages but the rate of cell proliferation in late passages was slower. ALN at moderate dose inhibited cell growth. ALN caused reduction of ALP activity in early passage. In contrast, extended passage responded differently to ALN by increasing ALP activity. Late passage showed higher collagen but lower osteocalcin gene expressions compared with early passage in the presence of ALN.
UNASSIGNED: An increase in passage number played critical role in cell morphology and activities as well as responses to the addition of an external factor. The effects of cell passage should be considered when used in basic science research and clinical applications.