Effect of static compressive force on in vitro cultured PDL fibroblasts: monitoring of viability and gene expression over 6 days

Abstract

Objectives

The aim was to investigate the impact of static compressive force (CF) application on human PDL-derived fibroblasts (HPDF) in vitro for up to 6 days on the expression of specific genes and to monitor cell growth and cell viability.

Materials and methods

CF of 2 g/cm2 was applied on HPDFs for 1–6 days. On each day, gene expression (cFOS, HB-GAM, COX2, IL6, TNFα, RUNX2, and P2RX2) and secretion (TNFα, PGE2) were determined by RT-qPCR and ELISA, respectively. Cell growth and cell viability were monitored daily.

Results

In comparison with controls, significant upregulation of cFOS in compressed HPDFs was observed. HB-GAM showed no changes in expression, except on day 5 (P < 0.001). IL6 expression was significantly upregulated from day 2–5, reaching the maximum on day 3 (P < 0.001). TNFα expression was upregulated on all but day 2. COX2 showed upregulation, reaching the plateau from day 3 (P < 0.001) until day 4 (P < 0.001), and returning to the initial state till day 6. P2RX7 was downregulated on days 2 and 4 to 6 (P < 0.001). RUNX2 was downregulated on days 2 and 5 (both P < 0.001). Cells in both groups were proliferating, and no negative effect on cell viability was observed.

Conclusion

Results suggest high molecular activity up to 6 days, therefore introducing further need for in vitro studies with a longer duration that would explain other genes and metabolites involved in orthodontic tooth movement (OTM).

Clinical relevance

Extension of an established in vitro force application system for prolonged force application (6 days) simulating the initial phase of OTM.

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Acknowledgments

The authors wish to thank Christine Schreindorfer and Lisa Müller (both from the Dept. of Orthodontics, LMU Munich) for their assistance in the lab work.

Funding

M.J.R. was funded by BAYHOST (Bayerisches Hochschulzentrum für Mittel-, Ost- und Südosteuropa, Regensburg, Germany).

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Correspondence to Uwe Baumert.

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Janjic Rankovic, M., Docheva, D., Wichelhaus, A. et al. Effect of static compressive force on in vitro cultured PDL fibroblasts: monitoring of viability and gene expression over 6 days. Clin Oral Invest 24, 2497–2511 (2020). https://doi.org/10.1007/s00784-019-03113-6

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Keywords

  • PDL fibroblasts
  • Compressive force
  • Orthodontic tooth movement
  • Gene expression