| First Author | Hamidi A | Year | 2022 |
| Journal | Cells | Volume | 11 |
| Issue | 10 | PubMed ID | 35626708 |
| Mgi Jnum | J:325159 | Mgi Id | MGI:7282561 |
| Doi | 10.3390/cells11101671 | Citation | Hamidi A, et al. (2022) Depletion of HIF-1alpha by Inducible Cre/loxP Increases the Sensitivity of Cultured Murine Hepatocytes to Ionizing Radiation in Hypoxia. Cells 11(10) |
| abstractText | The transcription factor hypoxia-inducible factor (HIF) is the main oxygen sensor which regulates adaptation to cellular hypoxia. The aim of this study was to establish cultured murine hepatocyte derived cells (mHDC) as an in vitro model and to analyze the role of HIF-1alpha in apoptosis induction, DNA damage repair and sensitivity to ionizing radiation (IR). We have crossed C57/BL6 mice that bear loxP sites flanking exon 2 of Hif1a with mice which carry tamoxifen-inducible global Cre expression. From the offspring, we have established transduced hepatocyte cultures which are permanently HIF-1alpha deficient after tamoxifen treatment. We demonstrated that the cells produce albumin, acetylcholine esterase, and the cytokeratins 8 and 18 which functionally characterizes them as hepatocytes. In moderate hypoxia, HIF-1alpha deficiency increased IR-induced apoptosis and significantly reduced the surviving fraction of mHDC as compared to HIF-1alpha expressing cells in colony formation assays. Furthermore, HIF-1alpha knockout cells displayed increased IR-induced DNA damage as demonstrated by increased generation and persistence of gammaH2AX foci. HIF-1alpha deficient cells showed delayed DNA repair after IR in hypoxia in neutral comet assays which may indicate that non-homologous end joining (NHEJ) repair capacity was affected. Overall, our data suggest that HIF-1alpha inactivation increases radiation sensitivity of mHDC cells. |
