Differences in RUNX2 and P2RX7 gene expression between mono- and coculture of human periodontal ligament cells and human osteoblasts under compressive force application.
OBJECTIVES
Objectives were (a) to establish an in vitro coculture model of human PDL-derived fibroblasts (HPDFs) and human alveolar bone-derived osteoblasts (HABOs), and (b) to measure RUNX2 and P2RX7 gene expression at multiple time points after compressive force (CF) stimulation for different durations.


SETTING/SAMPLE POPULATION
Human PDL-derived fibroblasts and HABOs from two individuals isolated from extracted teeth of healthy donors due to orthodontic reasons at LMU's Dental School were used.


MATERIALS AND METHODS
Mono- and cocultured cells were subjected to CF by centrifugation (47.4 g/cm2 ) for 1, 2 and 4 hours at 30°C. Total RNA was isolated before and 2, 4, 8, 16 minutes after CF application. Expression of RUNX2 and P2RX7 was determined using quantitative real-time polymerase chain reaction.


RESULTS
In monocultured cells, an upregulation of RUNX2 and P2RX7 expression was found after all CF durations: RUNX2 twofold in HPDFs after 4 hours (P = 0.002) and 1.7-fold in HABOs after 1 hour (P = 0.009) or 2 hours (P = 0.002) of CF. P2RX7 was significantly upregulated following 1 hour (P = 0.004) and 2 hours (P = 0.002) of CF application in HPDFS. In HABOs, a transient regulation was observed. In cocultured cells, a significant alleviation in gene expression was found for both loci after CF application. In both cell types, RUNX2 expression was significantly reduced in cocultured cells compared to cells in monoculture. P2RX7 expression showed significant attenuation in HPDFs only.


CONCLUSIONS
Cocultivation attenuated the CF induced increase of RUNX2 and P2RX7 gene expression in comparison to monoculture in both cell types. This suggests that intercellular communication may exist between HPDFs and HABOs.
['Shi|Jianwei|J|', 'Folwaczny|Matthias|M|', 'Wichelhaus|Andrea|A|https://orcid.org/0000-0001-8489-167X', 'Baumert|Uwe|U|https://orcid.org/0000-0002-4693-6969']
D002478:Cells, Cultured D018920:Coculture Techniques D050659:Core Binding Factor Alpha 1 Subunit D015870:Gene Expression D006801:Humans D010006:Osteoblasts D010513:Periodontal Ligament D058486:Receptors, Purinergic P2X7
RUNX2 P2RX7 coculture human osteoblasts compressive force human periodontal ligament fibroblasts