Table 4.
CircRNAs in MC3T3-E1 cells, rDFCs, and GFs cell lines.
| Reference | circRNA Name (Gene Name), Genome Location and Length | circRNA Target or Pathway | CircRNA Detection Method | Cell (Tissue) Details | Key Findings |
|---|---|---|---|---|---|
| Cao et al. 2021. [66] | circ_014154 | miR-145a-5p and let-7a-5p; MAPK pathway |
RT-qPCR RNA-seq |
MC3T3-E1 | 232 upregulated and 95 down-regulated circRNAs were found during osteogenic differentiation of MC3T3-E1 cells under microgravity; Circ_014154 was upregulated in MC3T3-E1 cells with osteogenic differentiation induced by microgravity via miR-145a-5p, let-7a-5p and the MAPK pathway. |
| Wu et al. 2020. [67] | mmu_circ_003795 | mmu‑miR‑1249‑5p COL15A1 |
RT-qPCR nucleic acid electro-phoresis Micro-array |
MC3T3‑E1 and MDPC23 cells; 24–72 h after transfection |
mmu_circ_003795 was increased after 72 h osteogensis in MC3T3-E1 and MDPC23 cells by RT-qPCR via mmu‑miR‑ 1249‑5p by targeting COL 15A1. |
| Cao et al. 2020. [68] | circ-Rtn4 | miR-146a | RT-qPCR Luciferase reporter assay |
exosomes from circRtn4-modified BMSCs MC3T3-E1 |
circRtn4 as miR-146a sponge to regulate exosomes from BMSCs reduced TNF-α induced cytotoxicity and inhibited apoptosis of MC3T3-E1. Luciferase reporter assay validated the binding between circRtn4 and mi-146a. |
| Mi et al. 2019. [69] | CircRNA AFF4 Mmu_circ_0000262 chr11:53182161-53194174; 12,013 bp |
miR-7223-5p; (PIK3R1) | RT-qPCR Luciferase reporter assay; micro-CT |
MC3T3-E1 |
In vitro—CircRNA AFF4 stimulated MC3T3-E1 proliferation and inhibited apoptosis via binding to miR-7223-5p, and its downstream target is PIK3R1. In vivo—circRNA AFF4 enhanced fracture healing in a mouse femur fracture model. |
| Du et al. 2019. [70] | circFgfr2 | miR-133 and BMP6 (bone morphogenetic protein-6); MAPK, TGF-β |
RT-qPCR RNA-seq |
Rat dental follicle cells (rDFCs) and tissues; passage 3 to 4. |
CircFgfr2 promotes osteogenic differentiation of rDFCs via miR-133/BMP6. In situ hybridization identified that circFgfr2 was upregulated in mandible dental follicle tissues at days 1 to 11 postnatally in Sprague-Dawley rats, while miR-133 was decreased. |
| Yang et al. 2017. [71] | circ-Amotl1 | miR-17-5p Stat3, Dnmt3a and fibronectin |
RT-qPCR | Human gingival fibroblast cell line CRL-2014; NIH 3T3 fibroblast cell line. | Circular-Amolt promoted in vivo skin wound healing. Circular-Amolt enhanced hGFs and NIH 3T3 cell migration; Circular-Amolt enhanced STAT3, Dnmt3a and fibronectin while suppressing the expression of miR-17-5p. |
Abbreviations: Rtn4: Reticulon 4; AFF4: ALL1-fused Gene from Chromosome 4/FMR2 Family Member 4; Fgfr2: Fibroblast growth factor receptor 2; Tgfbr2: Transforming Growth Factor Beta Receptor 2; MDPC23: Mouse Dental Papilla Cell; BMSCs: Bone marrow stromal cells; PIK3R1: Phosphoinositide-3-Kinase; COL15A1: Collagen alpha-1(XV); OPN: Osteopontin; MAPK: mitogen-activated protein kinases; TGF- β: transforming growth factor-beta; TNF-α: tumor necrosis factor alpha; B mircoCT: microcomputed tomography BMP6: Bone Morphogenetic Protein 6; MIR650: microRNA 650; LRRC4C: Leucine Rich Repeat Containing 4C; Amotl1: Angiomotin-like 1; STAT3: Signal transducer and activator of transcription 3; Dnmt3a: DNA Methyltransferase 3 Alpha; and THP1: human acute monocytic leukemia cell line.