Fig. 1

a Characterization of hPDLCs. Immunohistochemical staining showed the expression of vimentin in the cytoplasm (A, left), but keratin was not found (A, right). The insert shows a higher magnification of 200X. Scale bar, 100 μm. b The flow cytometry results showed that hPDLCs expressed mesenchymal stem cell-associated surface markers (CD73 and CD105) but did not express hematopoietic surface markers (CD34 and CD45). c Proliferation rates of hPDLCs. During the first 6 h, the proliferation rates of hPDLCs under hypoxia were higher than those of hPDLCs under normoxia. From 24 h to 72 h, the proliferation rates under hypoxia decreased. The values are presented as the mean ± SD (*Student’s t-test, P < 0.05). d hPDLCs under hypoxia expressed higher levels of HIF1a mRNA than control group hPDLCs