CircRNA Lrp6 promotes cementoblast differentiation via miR‐145a‐5p/Zeb2 axis

Abstract

Background and Objective: Cementum is a part of the periodontium and anchors periodontal ligaments to the alveolar bone. Cementoblasts are responsible for the cementum formation via matrix deposition and subsequently mineralization. Thus, exploring novel mechanisms underlying the function of cementoblast contributes to the treatment of cementum damage. Recently, circRNA Lrp6 (circLRP6) has been of interest due to its active role in cell differentiation, but its potential role in cementoblast differentiation remains unclear. Herein, we attempted to elucidate the role of circLRP6 in cementoblast differentiation and clarify any associated mechanisms. Material and Methods:The mRNA expressions of circLRP6, miR-145a-5p, zinc finger E-box binding homeobox 2 (Zeb2), runt-related transcription factor 2 (Runx2), osteopontin (Opn), and bone sialoprotein (Bsp) were evaluated by qRT-PCR. The protein levels of Zeb2 were measured by Western blot. Bioinformatic analysis and dual-luciferase reporter assays were used to test the potential binding targets of miR-145a-5p. The differentiation potentials of the cementoblasts were assessed by Alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin red S (ARS) staining, and quantification.Results: In this study, circLRP6 was significantly upregulated in cementoblast differentiation. Furthermore, circLRP6 knockdown inhibited ALP levels, reduced calcium nodule formation and the expression of Runx2, Opn, and Bsp. Mechanically, bioinformatic analysis and dual-luciferase reporter assays confirmed miR-145a-5p was a potential binding target of circLRP6. miR-145a-5p can negatively regulate cementoblast differentiation. Subsequently, bioinformatic analysis and dual-luciferase reporter assays confirmed Zeb2 was a potential miR-145a-5p target. miR-145a-5p overexpression resulted in a downregulation of Zeb2. Furthermore, Zeb2 inhibition partially reversed the effect of circLRP6 during cementoblast differentiation. Conclusion:Taken together, circLRP6 appears to modulate cementoblast differentiation by antagonizing the function of miR-145a-5p, thereby increasing Zeb2. This study serves as a stepping stone for the potential development of an approach to promote cementum formation.

Expression profile analysis of long noncoding RNA and messenger RNA during mouse cementoblast mineralization

“…However, the majority of lncRNAs have not been investigated for roles in cementoblast mineralization in vitro and in vitro. Although previous research has demonstrated that CircRNA Lrp6 promotes cementoblast mineralization, 43 circular RNA expression profile was not determined by RNA sequencing during cementoblast mineralization. Meanwhile, the roles of lncRNAs in epigenetics are still unexplored during cementoblast mineralization.…”

Circular RNA‐circLRP6 protects cardiomyocyte from hypoxia‐induced apoptosis by facilitating hnRNPM‐mediated expression of FGF‐9

“…The circLRP6 2-2 -probe-captured FGF9 mRNAs were analyzed by qPCR. **P < 0.01. involved in cell cycle, proliferation, and apoptosis of cells including tumor cells and smooth muscle cells [17][18][19][20][21][22], they might not show the same effect in cardiomyocytes. Moreover, according to the RNA-seq data of Werfel et al [8], only circRNA formed by the second exon of LRP6 gene was robustly detected in heart samples of species across human, mouse, and rat, implying its evolutionary indispensability in animal hearts.…”

“…Dysregulation of these circRNAs will result in heart diseases [5,15,16]. Although other distinct circular transcripts of LRP6 were reported to be involved in cell cycle, proliferation, and apoptosis of cells including tumor cells and smooth muscle cells [17–22], they might not show the same effect in cardiomyocytes. Moreover, according to the RNA‐seq data of Werfel et al .…”

Identification of potentially functional circRNAs and prediction of circRNA‐miRNA‐mRNA regulatory network in periodontitis: Bridging the gap between bioinformatics and clinical needs

“…For osteoblast, circ_0008500 remained upregulated during osteoblast differentiation and promoted osteoblast mineralization via sponging miR‐1301‐3p 52 . One recent study showed that circLrp6 promoted cementoblast differentiation by regulating Zeb2 53 …”