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Updated: Oct 13, 2025
Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
Published on: October 4, 2024
Optogenetic control of cancer cell survival in ChR2-transfected HeLa cells
Claudio Córdova1, Carlo Lozano2, Belén Rodríguez1
1Laboratorio de Estructura y Función Celular, Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.
Abstract:
Optogenetics is a molecular biological technique involving transfection of cells with photosensitive proteins and the subsequent study of their biological effects. The aim of this study was to evaluate the effect of blue light on the survival of HeLa cells, transfected with channelrhodopsin-2 (ChR2). HeLa wild-type cells were transfected with a plasmid that contained the gene for ChR2. Transfection and channel function were evaluated by real-time polymerase chain reaction (RT-PCR), fluorescence imaging using green fluorescent protein (GFP) and flow cytometry for intracellular calcium changes using a Fura Red probe. We developed a platform for optogenetic stimulation for use within the cell culture incubator. Different stimulation procedures using blue light (467 nm) were applied for up to 24 h. Cell survival was determined by flow cytometry using propidium iodide and rhodamine probes. Change in cell survival showed a statistically significant (p < 0.05) inverse association with the frequency and time of application of the light stimulus. This change seemed to be associated with the ChR2 cis-trans-isomerization cycle. Cell death was associated with high concentrations of calcium in the cytoplasm and stimulation intervals less than the period of isomerization. It is possible to transfect HeLa cells with ChR2 and control their survival under blue light stimulation. We suggest that this practice should be considered in the future development of optogenetic systems in biological or biomedical research.
Insights
Optogenetics allows control over HeLa cell survival using blue light stimulation after transfection with channelrhodopsin-2 (ChR2). Cell death is linked to high calcium levels and specific light stimulation intervals.
Area of Science:
- Molecular Biology
- Optogenetics
- Cell Biology
Background:
- Optogenetics utilizes photosensitive proteins to study cellular functions.
- Channelrhodopsin-2 (ChR2) is a photosensitive protein used in optogenetic research.
- Controlling cell survival via optogenetics is crucial for biomedical applications.
Purpose of the Study:
- To investigate the impact of blue light on the survival of HeLa cells engineered with ChR2.
- To establish a method for optogenetic control of cell survival in a cell culture environment.
Main Methods:
- HeLa cells were transfected with the ChR2 gene.
- Transfection and ChR2 function were confirmed using RT-PCR, fluorescence imaging (GFP), and flow cytometry (intracellular calcium).
- A custom platform delivered blue light (467 nm) stimulation for up to 24 hours; cell survival was assessed via flow cytometry (propidium iodide, rhodamine).
Main Results:
- A statistically significant inverse relationship was observed between light stimulation frequency/duration and HeLa cell survival (p < 0.05).
- Cell death correlated with elevated intracellular calcium levels and stimulation intervals shorter than the ChR2 isomerization cycle.
- Successful transfection and optogenetic control of cell survival were demonstrated.
Conclusions:
- HeLa cells can be successfully transfected with ChR2 for controlled survival under blue light.
- The findings suggest potential applications in developing future optogenetic systems for biological and biomedical research.
- Understanding the ChR2 cis-trans-isomerization cycle is key to managing cell survival during optogenetic stimulation.
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