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Roennfeldt AE, Allen TP, Trowbridge BN, Beard MR, Whitelaw ML, Russell DL, Bersten DC, Peet DJ. NanoFIRE: A NanoLuciferase and Fluorescent Integrated Reporter Element for Robust and Sensitive Investigation of HIF and Other Signalling Pathways. Biomolecules 2023; 13:1545. [PMID: 37892227 PMCID: PMC10605489 DOI: 10.3390/biom13101545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/16/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
The Hypoxia Inducible Factor (HIF) transcription factors are imperative for cell adaption to low oxygen conditions and development; however, they also contribute to ischaemic disease and cancer. To identify novel genetic regulators which target the HIF pathway or small molecules for therapeutic use, cell-based reporter systems are commonly used. Here, we present a new, highly sensitive and versatile reporter system, NanoFIRE: a NanoLuciferase and Fluorescent Integrated Reporter Element. Under the control of a Hypoxic Response Element (HRE-NanoFIRE), this system is a robust sensor of HIF activity within cells and potently responds to both hypoxia and chemical inducers of the HIF pathway in a highly reproducible and sensitive manner, consistently achieving 20 to 150-fold induction across different cell types and a Z' score > 0.5. We demonstrate that the NanoFIRE system is adaptable via substitution of the response element controlling NanoLuciferase and show that it can report on the activity of the transcriptional regulator Factor Inhibiting HIF, and an unrelated transcription factor, the Progesterone Receptor. Furthermore, the lentivirus-mediated stable integration of NanoFIRE highlights the versatility of this system across a wide range of cell types, including primary cells. Together, these findings demonstrate that NanoFIRE is a robust reporter system for the investigation of HIF and other transcription factor-mediated signalling pathways in cells, with applications in high throughput screening for the identification of novel small molecule and genetic regulators.
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Affiliation(s)
- Alison E. Roennfeldt
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
- Robinson Research Institute, School of Biomedicine, The University of Adelaide, Adelaide, SA 5006, Australia;
| | - Timothy P. Allen
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
| | - Brooke N. Trowbridge
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Michael R. Beard
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Murray L. Whitelaw
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
- ASEAN Microbiome Nutrition Centre, National Neuroscience Institute, Singapore 169857, Singapore
| | - Darryl L. Russell
- Robinson Research Institute, School of Biomedicine, The University of Adelaide, Adelaide, SA 5006, Australia;
| | - David C. Bersten
- Robinson Research Institute, School of Biomedicine, The University of Adelaide, Adelaide, SA 5006, Australia;
| | - Daniel J. Peet
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (A.E.R.); (T.P.A.); (B.N.T.); (M.R.B.); (M.L.W.)
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Inducible disruption of the c-myb gene allows allogeneic bone marrow transplantation without irradiation. J Immunol Methods 2018; 457:66-72. [PMID: 29630967 DOI: 10.1016/j.jim.2018.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/25/2018] [Accepted: 03/26/2018] [Indexed: 12/31/2022]
Abstract
Allogeneic bone marrow (BM) transplantation enables the in vivo functional assessment of hematopoietic cells. As pre-conditioning, ionizing radiation is commonly applied to induce BM depletion, however, it exerts adverse effects on the animal and can limit experimental outcome. Here, we provide an alternative method that harnesses conditional gene deletion to ablate c-myb and thereby deplete BM cells, hence allowing BM substitution without other pre-conditioning. The protocol results in a high level of blood chimerism after allogeneic BM transplantation, whereas immune cells in peripheral tissues such as resident macrophages are not replaced. Further, mice featuring a low chimerism after initial transplantation can undergo a second induction cycle for efficient deletion of residual BM cells without the necessity to re-apply donor cells. In summary, we present an effective c-myb-dependent genetic technique to generate BM chimeras in the absence of irradiation or other methods for pre-conditioning.
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Lent-On-Plus Lentiviral vectors for conditional expression in human stem cells. Sci Rep 2016; 6:37289. [PMID: 27853296 PMCID: PMC5112523 DOI: 10.1038/srep37289] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 10/28/2016] [Indexed: 12/25/2022] Open
Abstract
Conditional transgene expression in human stem cells has been difficult to achieve due to the low efficiency of existing delivery methods, the strong silencing of the transgenes and the toxicity of the regulators. Most of the existing technologies are based on stem cells clones expressing appropriate levels of tTA or rtTA transactivators (based on the TetR-VP16 chimeras). In the present study, we aim the generation of Tet-On all-in-one lentiviral vectors (LVs) that tightly regulate transgene expression in human stem cells using the original TetR repressor. By using appropriate promoter combinations and shielding the LVs with the Is2 insulator, we have constructed the Lent-On-Plus Tet-On system that achieved efficient transgene regulation in human multipotent and pluripotent stem cells. The generation of inducible stem cell lines with the Lent-ON-Plus LVs did not require selection or cloning, and transgene regulation was maintained after long-term cultured and upon differentiation toward different lineages. To our knowledge, Lent-On-Plus is the first all-in-one vector system that tightly regulates transgene expression in bulk populations of human pluripotent stem cells and its progeny.
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