Figure 6. Expression of differentiation markers in induced HDPCs by real-time RT-PCR. HDPCs were induced with (a) osteogenic, (b) adipogenic, or (c) chondrogenic factors for 28 days and the expression levels of typical differentiation markers for each lineage were examined by RT-PCR. Data are presented as means ± standard deviations (n = 10, p < 0.05)^*. HDPCs, human dental pulp cells; RT-PCR, real-time quantitative reverse-transcription polymerase chain reaction; OG, HDPCs-OG group; ED, HDPCs-ED group; Combined, HDPCs-Combined group; C, control group which were maintained in medium without inducers; T, treated group which were induced to undergo adipogenic, osteogenic, or chondrogenic differentiation using an MSC functional identification kit; HDPCs-OG, HDPCs were isolated by the outgrowth method; HDPCs-ED, HDPCs were isolated by the enzymatic digestion method (collagenase/dispase/trypsin); HDPCs-Combined, HDPCs were isolated by the combination of both methods; ALP, alkaline phosphatase; BSP2, bone sialoprotein2; COL1A1, collagen type-I alpha-1; OCN, osteocalcin; ON, osteonectin; OPN, osteopontin; OSX, osterix; RUNX2, runt-related transcription factor 2; LPL, lipoprotein lipase; PPAR-γ, peroxisome proliferator-activated receptor-gamma; ACAN, aggrecan; COL2A1, collagen type-II alpha-1; COL10A1, collagen type-X; and SOX9, sex-determining region Y-box 9.