Supplementary Material for: Mechanical Force-Induced Specific MicroRNA Expression in Human Periodontal Ligament Stem Cells

It remains unclear how the expression of microRNAs (miRNAs) in human
periodontal ligament stem cells (PDLSCs) might respond to mechanical
stretch. To investigate specific miRNA expression in stretched PDLSCs,
we used a Flexcell® FX-5000™ tension system to achieve external
mechanical stimulation. Then, a custom-designed microarray assay was
performed to investigate and describe the genome-wide differential
expression of miRNAs in normal and stretched PDLSCs. Finally, we
implemented integrative miRNA target prediction and network analysis
approaches to construct an interaction network of the key miRNAs and
their putative targets. We found that stretching induced morphological
changes and increased alkaline phosphatase (ALP) activity, runt-related
transcription factor 2 (RUNX2), osteocalcin (OCN), and bone sialoprotein
(BSP) expression in PDLSCs. The microarray data showed that 53 miRNAs
were differentially expressed with stretching. With an interaction
network, we examined the connections between 10 selected key miRNAs and
their putative target genes, which were related to mechanical force. The
results from the interaction network provided a basis for postulating
the functional roles of miRNAs in PDLSCs.