Keong Jia Yee, Low Li Wei, Chong Jean Mun, Ong Yan Yi, Pulikkotil Shaju Jacob, Singh Gurbind, Nagendrababu Venkateshbabu, Banavar Spoorthi Ravi, Khoo Suan Phaik
School of Dentistry, International Medical University, Kuala Lumpur, Malaysia.
Department of Periodontology and Implantology, School of Dentistry, International Medical University, Kuala Lumpur, Malaysia.
Saudi Dent J. 2020 Mar;32(3):148-154. doi: 10.1016/j.sdentj.2019.08.001. Epub 2019 Aug 23.
Periodontal ligament stem cells (PDLSCs) have considerable potential for use as a means of achieving periodontal regeneration due to their noteworthy proliferative properties and secretory functions. In particular, PDLSCs secrete vascular endothelial growth factor (VEGF) which enhances angiogenesis and osteogenesis. The resulting repair and development of blood vessels and hard tissues which would occur in the presence of these cells could be central to an effective periodontal regeneration procedure.The bacterial biofilm of tooth surface related to the periodontium might provide either an inhibition or a stimulus to different factors involved in a regenerative process. Cell culture experiments have been investigated by adding lipopolysaccharide (LPS) to the culture medium but the effect of various concentration of LPS in these circumstances has not been investigated. Therefore, this study aimed to investigate the effect of LPS concentrations on proliferation of PDLSCs and on their secretion of VEGF.
PDLSCs were treated with 0, 5, 10 and 20 µg/mL of LPS. At 48 and 96 h, total cell numbers of control and LPS treated PDLSCs were counted by haemocytometer under a microscope. The VEGF concentration in the conditioned media of the PDLSCs was measured by ELISA.
Rate of cell proliferation of PDLSCs decreased significantly in all LPS treated groups at both 48 h and 96 h except for the group treated with 5 µg/mL of LPS at 48 h. At both 48 and 96 h, VEGF secretion from PDLSCs was reduced significantly at all three LPS concentrations. There was no statistically significant difference in cell proliferation and the amount of VEGF secretion of PDLSCs among the groups treated with different LPS concentrations. No statistically significant change was found in cell proliferation of LPS treated PDLSCs over time, whereas VEGF secretion of PDLSCs was found to have increased significantly with time despite the LPS treatment.
LPS reduced cell proliferation and VEGF secretion of PDLSCs, suggesting that periodontal pathogens might reduce the capability of PDLSCs in periodontal regeneration. Yet, LPS treated PDLSCs remained viable and VEGF secretion increased significantly over time. Further research is needed to study the potential use of PDLSCs in periodontal regeneration and the relationship of biofilm LPS accumulations.
牙周膜干细胞（PDLSCs）因其显著的增殖特性和分泌功能，在牙周组织再生方面具有巨大潜力。特别是，PDLSCs分泌血管内皮生长因子（VEGF），可促进血管生成和骨生成。在这些细胞存在的情况下，血管和硬组织的修复与发育对于有效的牙周再生过程可能至关重要。与牙周组织相关的牙面细菌生物膜可能对再生过程中涉及的不同因素产生抑制或刺激作用。已有通过向培养基中添加脂多糖（LPS）进行细胞培养实验的研究，但尚未研究不同浓度LPS在此情况下的作用。因此，本研究旨在探讨LPS浓度对PDLSCs增殖及其VEGF分泌的影响。
用0、5、10和20μg/mL的LPS处理PDLSCs。在48小时和96小时时，通过血细胞计数器在显微镜下计数对照和LPS处理的PDLSCs的总细胞数。用酶联免疫吸附测定法（ELISA）测量PDLSCs条件培养基中的VEGF浓度。
除48小时时用5μg/mL LPS处理的组外，在48小时和96小时时，所有LPS处理组的PDLSCs细胞增殖率均显著降低。在48小时和96小时时，所有三种LPS浓度下PDLSCs的VEGF分泌均显著减少。不同LPS浓度处理组之间，PDLSCs的细胞增殖和VEGF分泌量无统计学显著差异。LPS处理的PDLSCs细胞增殖随时间无统计学显著变化，而尽管有LPS处理，PDLSCs的VEGF分泌随时间显著增加。
LPS降低了PDLSCs的细胞增殖和VEGF分泌，表明牙周病原体可能降低PDLSCs在牙周再生中的能力。然而，LPS处理的PDLSCs仍保持活力，且VEGF分泌随时间显著增加。需要进一步研究以探讨PDLSCs在牙周再生中的潜在用途以及生物膜LPS积累的关系。
