Abstract
Purpose: :
To investigate role of Kruppel-like factor 5 (KLF5) in human limbal stem cells (hLSCs), we performed this study.
Methods: :
Human limbal stem cells (hLSCs) was isolated from corneo-scleral rim of donor after corneal transplantation. The human corneo-scleral rim was used by approval of the Eye Gene and Tissue Bank in the Catholic University. Human limbal stem cells (hLSCs) were co-cultured with MMC treated mouse NIH 3T3 cell. And the expression of KLF5 was observed by RT-PCR, westernblot analysis and immune-fluorescence staining. Inhibition of KLF5 expression was performed by transfection of siRNA. Also, we used HaCaT cells as KLF5 expression cell. The cell proliferation was observed by BrdU incorporation assay. The stemness of limbal stem cells was confirmed by colony forming efficacy.
Results: :
We found that KLF5 transcription factor was normally expressed in both hLSCs colonies and HaCaT cells. However, KLF5 did not expressed in the other cells, such as corneal epithelium, limbal epithelium, NIH 3T3. The gene expression was confirmed by immunostaining and RT-PCR. After treatment of KLF5 siRNA, its mRNA level was decreased in the HaCaT cells and hLSCs. In HaCaT cells, the suppression of KLF5 expression induced inhibition of proliferation and cell cycle arrest. In the limbal stem cells, the suppression of KLF5 expression inhibited the stem cell proliferation and colony formation.
Conclusions: :
These results suggested that the KLF5 transcription factor is the key factor for proliferation of LSCs and maintenance of stemness.