A Human Periodontal Ligament Fibroblast Cell Line as a New Model to Study Periodontal Stress

Abstract

The periodontal ligament (PDL) is exposed to different kinds of mechanical stresses such as bite force or orthodontic tooth movement. A simple and efficient model to study molecular responses to mechanical stress is the application of compressive force onto primary human periodontal ligament fibroblasts via glass disks. Yet, this model suffers from the need for primary cells from human donors which have a limited proliferative capacity. Here we show that an immortalized cell line, PDL-hTERT, derived from primary human periodontal ligament fibroblasts exhibits characteristic responses to glass disk-mediated compressive force resembling those of primary cells. These responses include induction and secretion of pro-inflammatory markers, changes in expression of extracellular matrix-reorganizing genes and induction of genes related to angiogenesis, osteoblastogenesis and osteoclastogenesis. The fact that PDL-hTERT cells can easily be transfected broadens their usefulness, as molecular gain- and loss-of-function studies become feasible.

Dental follicle cell differentiation towards periodontal ligament-like tissue in a self-assembly three-dimensional organoid model

“…A major limitation of this study was the implementation of the immortalised PDL cell line, rather than primary PDL cells. Previous studies demonstrated the PDL phenotype stability of the cell line (Docheva et al, 2010) as well as its successful use as a PDL model in vitro (Ern et al, 2017;Hsieh et al, 2016;Weider et al, 2020). Moreover, the PDL-hTERT cells were capable of forming tendon/ligament-like tissues in vivo when implanted as cell pellets in a rat Achilles tendon defect model (Hsieh et al, 2016).…”

“…collagen Johansson, 2019; Vo et al, 2020). Epidemiological studies suggest that over 50 % of the adult population is suffering from periodontitis (Romandini et al, 2021).…”

“…according to AllCells company regulations, further donor information such gender and exact age was not provided to the purchaser). The PDL-hTERT immortal cell line has already been established and characterised (Docheva et al, 2010;Ern et al, 2017;Hsieh et al, 2016;Weider et al, 2020). Both cell types were cultured in low-glucose DMEM (Gibco, Karlsruhe, Germany), supplemented with 10 % FBS and 1 % penicillin (10,000 units/mL) / streptomycin (10 mg/mL) solution (all from Sigma-Aldrich).…”

In Vitro Compression Model for Orthodontic Tooth Movement Modulates Human Periodontal Ligament Fibroblast Proliferation, Apoptosis and Cell Cycle

“…Recently it was shown that the hPDLF response to mechanical stress is associated with an expression of inflammatory markers and enhanced cytokine production [27]. To confirm the effectiveness of the used in vitro compressive force model, several inflammatory markers were investigated by real-time (RT) qPCR analysis.…”

Mechanical Compression by Simulating Orthodontic Tooth Movement in an In Vitro Model Modulates Phosphorylation of AKT and MAPKs via TLR4 in Human Periodontal Ligament Cells

“…Mechanical stimuli, initially directed to the ECM of the PDL, are transduced via mechanosensitive receptors, ion channels [ 7 ] and pattern recognition receptors (PRR) to biochemical responses. This leads to a local sterile inflammation with pro-inflammatory cytokines, e.g., interleukins (IL-6, IL-8) [ 8 , 9 , 10 ], vascular endothelial growth factor (VEGF) [ 11 ] and matrix metalloproteinases (MMP8 and 9) [ 10 , 12 ]. MMPs are a group of enzymes that in concert are responsible for the degradation of most extracellular matrix proteins during organogenesis, growth and normal tissue turnover and increase significantly in various pathological conditions [ 13 ] and serve to accurately predict the level of inflammation during OTM [ 14 ].…”