Effects of sodium chloride on the gene expression profile of periodontal ligament fibroblasts during tensile strain

Abstract

Purpose During orthodontic tooth movement, pressure and tension zones develop in the periodontal ligament, and periodontal ligament fibroblasts (PDLF) become exposed to mechanical strain. Enhanced salt (NaCl) concentrations are known to modulate responses of PDLF and immune cells to different stimuli like mechanical strain. Here, we investigated the impact of tensile strain on the gene expression profile of PDLF under normal (NS) and high salt (HS) conditions. Methods After preincubation under NS or HS (+40 mM NaCl in medium) conditions for 24 h, PDLF were stretched 16% for 48 h using custom-made spherical cap silicone stamps using an established and published setup. After determination of cell number and cytotoxicity, we analyzed expression of genes involved in extracellular matrix reorganization, angiogenesis, bone remodeling, and inflammation by quantitative real-time polymerase chain reaction (RT-qPCR). Results Tensile strain did not affect the expression of genes involved in angiogenesis or extracellular matrix reorganization by PDLF, which however modulate inflammatory responses and bone remodeling in reaction to 16% static tensile strain. Salt (NaCl) treatment triggered enhanced extracellular matrix formation, expression of cyclooxygenase 2 and bone metabolism in PDLF during tensile strain. Conclusions Salt (NaCl) consumption may influence orthodontic tooth movement and periodontal bone loss via modulation of extracellular matrix and bone metabolism. Excessive salt intake during orthodontic therapy may cause adverse effects regarding periodontal inflammation and bone resorption.

Effects of mechanical strain on periodontal ligament fibroblasts in presence of Aggregatibacter actinomycetemcomitans lysate

“…Increased catabolic dynamics at orthodontic compression zones were previously corroborated in vivo via RANKL upregulation [ 38 ] and are consistent with our results. Contrary to previous results [ 43 ], RANKL gene expression was not downregulated after tensile strain in this study. In another recent study, the authors observed a trend for increased RANKL gene expression which was then associated with a reduced RANKL secretion [ 44 ].…”

An Evaluation of Different 3D Cultivation Models on Expression Profiles of Human Periodontal Ligament Fibroblasts with Compressive Strain

“…In a complex 3D environment, such as the periodontal ligament in vivo, the initially applied force vector is probably divided and diverted into several smaller force vectors pointing into different directions. In some areas of the 3D matrix, this may even induce zones of tension favouring OPG over RANKL induction to initiate bone apposition [54,55]. This may be another explanation for the differences in RANKL and OPG expression in different 3D cultures and requires further research.…”

Differential gene expression response of synovial fibroblasts from temporomandibular joints and knee joints to dynamic tensile stress

“…Mastercycler ® ep realplex-S thermocycler, Eppendorf AG, Hamburg, Germany). We calculated relative gene expression using a set of two reference genes which proved to be suitable for the used experimental setup based on the 2 -Cq method (Cq = Cq (target gene) -Cq (geometric mean Hprt/Sdha)) [49,50]. All primers (Table 1; Eurofins MWG, Ebersberg, Germany) were constructed with NCBI PrimerBLAST [10].…”