The Expression and Regulatory Roles of Long Non-Coding RNAs in Periodontal Ligament Cells: A Systematic Review

Abstract

Periodontal ligament (PDL) cells play a pivotal role in periodontal and bone homeostasis and have promising potential for regenerative medicine and tissue engineering. There is compelling evidence that long non-coding RNAs (lncRNAs) are differentially expressed in PDL cells compared to other cell types and that these lncRNAs are involved in a variety of biological processes. This study systematically reviews the current evidence regarding the expression and regulatory functions of lncRNAs in PDL cells during various biological processes. A systematic search was conducted on PubMed, the Web of Science, Embase, and Google Scholar to include articles published up to 1 July 2021. Original research articles that investigated the expression or regulation of lncRNAs in PDL cells were selected and evaluated for a systematic review. Fifty studies were ultimately included, based on our eligibility criteria. Thirteen of these studies broadly explored the expression profiles of lncRNAs in PDL cells using microarray or RNA sequencing. Nineteen studies investigated the mechanisms by which lncRNAs regulate osteogenic differentiation in PDL cells. The remaining 18 studies investigated the mechanism by which lncRNAs regulate the responses of PDL cells to various stimuli, namely, lipopolysaccharide-induced inflammation, tumor necrosis factor alpha-induced inflammation, mechanical stress, oxidative stress, or hypoxia. We systematically reviewed studies on the expression and regulatory roles of lncRNAs in diverse biological processes in PDL cells, including osteogenic differentiation and cellular responses to inflammation, mechanical stress, and other stimuli. These results provide new insights that may guide the development of lncRNA-based therapeutics for periodontal and bone regeneration.

Periodontal ligament cells from patients with treated stable periodontitis: Characterization and osteogenic differentiation potential

“…The molecular mechanism of rescuing the PDL cells of inflamed periodontal tissue and improving their regenerative potential has long been discussed. 15,17,18,21,38 Recent evidence has suggested that AKT signaling is related to the osteogenic differentiation of PDL cells, 39,40 and the activation of AKT signaling restores Toll-like receptormediated inhibition of osteogenic differentiation in PDL cells. 40 Our results show that after osteogenic induction, AKT signaling was less activated in I-PDL and S-PDL cells than in H-PDL cells.…”

Cartilage Endplate-Derived Stem Cells for Regeneration of Intervertebral Disc Degeneration: An Analytic Study

“…The quality of included papers was assessed using a quality scoring system, 47 which included eight questions and has been widely used in similar publications with "yes" and "no" answers assigned 1 and 0 points, respectively. [48][49][50][51] The maximum achievable score is 8 points. The quality scores for included studies were independently determined.…”

“…A score of 7-8 was interpreted as excellent, 5-6 as good, 3-4 as poor, and 0-2 as bad. [48][49][50][51]…”

Long non‐coding RNA LncTUG1 regulates favourable compression force‐induced cementocytes mineralization via PU.1/TLR4/SphK1 signalling

“… 14 Recent studies have demonstrated that lncRNAs mediate mechanical stress‐induced osteogenic mineralization of periodontal ligament stem cells (PDLSCs) to control periodontal homeostasis. 15 , 16 Also playing a role in periodontal homeostasis and acting as the primary root cell type to sense orthodontic forces, 17 cementocytes could likewise transduce mechanical signals 5 , 17 into biological responses that modulate cementum mineralization in a lncRNAs‐based regulatory manner. However, the potential mechanisms of such cellular events are yet to be studied.…”

“…In a post‐transcriptional regulation manner, lncRNA SNHG1 upregulated DNA methyltransferase 1 (DNMT1) expression, resulting in osteoprotegerin (OPG) hypermethylation and decreased OPG expression, in turn contributing to osteoporosis 14 . Recent studies have demonstrated that lncRNAs mediate mechanical stress‐induced osteogenic mineralization of periodontal ligament stem cells (PDLSCs) to control periodontal homeostasis 15,16 . Also playing a role in periodontal homeostasis and acting as the primary root cell type to sense orthodontic forces, 17 cementocytes could likewise transduce mechanical signals 5,17 into biological responses that modulate cementum mineralization in a lncRNAs‐based regulatory manner.…”