Fig. 1

Establishment of the immortalized HERS cell lines and they expressed markers specific to HERS cells. a Isolation of HERS cells from PN8 rat first mandibular molars. b The primary HERS cells showed a typical cobblestone-like appearance. c SV40 T-Ag was present in the nucleus of the immortalized HERS cells. d Compared with the primary cells, the two cell lines showed an epithelial morphology and are a little bit elongated. e CCK-8 assay was used to compare the proliferation rate of the primary cells, HERS-H1 and HERS-C2. f The primary HERS cells expressed both epithelial cell markers CK14, E-cadherin, and mesenchymal cell markers vimentin. The immortalized cells HERS-C2 and HERS-H1 also expressed CK14, E-cadherin, and vimentin stably at least from passage 2 to passage 20. Scale bars are shown. (*P < 0.05, HERS-H1 vs. primary HERS cells; #P < 0.05, HERS-C2 vs. primary HERS cells, Scale bar: 100 μm in b and d)