Optogenetics applied to HTS
At Axxam, we have applied the advantages of optogenetic technologies to build in vitro assays, with significant enhancements in content, precision, and biological relevance. From 2D to 3D advanced models, optogenetics has been used to increase confidence in early drug discovery phases, as well as to support clinical development of gene therapy optogenetic drugs.
Optogenetics is one of the fastest growing and most promising technologies of recent years: the use of genetically encoded elements which activity can be modulated by light has in fact completely revolutionized the manipulation and investigation of biological processes.
Optogenetic tools can provide significant improvement compared to the classical “chemical” approaches achieving a precise control of many cellular pathways and allowing the modulation of single biological processes in a not-invasive and reversible manner, with a milliseconds timescale, and a cellular specificity in a way you cannot reach with the classical drug application, or even with electrical stimulation.
Optogenetic technologies combine the two fundamental concepts of spatial resolution and temporal resolution, to obtain a technique able to control a cellular response in a fast and repetitive way, acting only on a specific gene, in a specific cell line or cell compartment.
1. Optogenetics for Drug Discovery
Optogenetics combines genetic engineering and optics to control cell functions with light, with millisecond temporal resolution and full reversibility. In early drug discovery, we express the target of interest with a light-sensitive actuator (ion channel, pump, or enzyme). Light replaces non-physiological chemical triggers, and the response is followed with standard optical readouts. All our assays are miniaturized to 384-well format and fully compatible with our HTS kinetic plate reader platform (e.g. Volta, FLIPR, FDSS, Pherastar) as well as High Content imaging platform. In addition, light-controlled patch-clamp platforms are used to fully validate target functionality at the electrophysiological level.
1.1 Optogenetics at plate reader: 2D and 3D models
We have developed both recombinant immortalized cell lines and iPSC-derived cardiomyocytes 2D cellular models, using optogenetic technologies and our kinetic plate reader.
In this context, light-actuators (such as Channelrhodopsin-2, bPAC or Split-bPAC-K) are used to optically control CaV or NaV channels, NCX1 transporter, HCN1 or HCN2 ion channels.
Moreover, genetically encoded sensors of voltage, calcium, and cAMP are applied to allow all-optical detection of ion channels, transporters and Gs/Gi-coupled GPCRs. The superior time resolution and physiological reversibility of the light trigger allowed the characterization of state- and use-dependent ion channel blockers, as well as drug testing on light-paced iPSC-derived cardiomyocytes at controlled beating frequencies. Moreover, pairing optogenetic stimulation with high-content imaging adds single-cell and subcellular resolution to light-controlled assays, allowing light stimulation and analysis of thousands of cells per acquisition. This is especially valuable for heterogeneous and physiologically relevant models such as cardiac or neuronal cultures, and stem cell-derived cells.
Optogenetic assays have also been validated with 3D advanced models, in line with our NAMs translational approach: thanks to our high-speed kinetic plate reader equipped with msec timescale optical pacing, 3D-cardiac models can be paced by light, enabling the study of drug effects on calcium or voltage kinetics at controlled beating frequencies.
1.2 Optogenetics in Electrophysiology
In addition, to complete the characterization of cell lines cellular assays expressing optically controlled ion channels, we have also setup an “Opto manual patch-clamp platform”.
The system integrates a broad-spectrum LED illumination device that allows to deliver light pulses of programmable intensity, duration and wavelength while performing voltage- or current-clamp experiments. With this setup, we successfully check the purity of in-house engineered clones stably expressing light-gated channel (like Channelrhodopsin-2) alone or together with voltage-, ligand-gated ion channels (for instance NaV1.5).
This activity is mandatory not only to confirm the results obtained with the plate reader functional flux assay but also to establish a strong correlation between these techniques used along the drug discovery cascade. In parallel, optogenetic stimulation capabilities are also available on the SyncroPatch 384 and on the MEA Maestro Pro platforms through integrated OptoTool and Lumos™ modules respectively, enabling optical stimulation protocols in combination with high-throughput electrophysiological and network activity recordings.
Do you need more information on optogenetics in drug discovery?
To learn how optogenetics has revolutionized drug screening, read the following articles:
V. Agus et al., Springer (2024)V. Agus et al., SLAS Discov (2021)
V. Agus et al., SLAS Discov (2018)
H. Zhang et al., Trends Biotechnol (2017)
V. Agus et al., Curr Opin Biotechnol (2017)
Explore our case studies:
2. Optogenetics for Clinical Studies
In the last years, optogenetics has quickly reached the clinical stage, with gene therapy strategies designed to restore light sensitivity in degenerated tissues such as the retina. For these complex biological medicines, a potency assay is a mandatory requirement to support clinical studies and drug licensing.
Axxam develops and validates cell-based potency assays for gene therapy drugs, including those based on optogenetic proteins. Our assays measure the biological function of the product in a therapeutic-relevant modality, and are developed and qualified in line with international guidelines for clinical development, to support batch release and stability studies from early clinical phases to pivotal studies.
Our offer covers assay development and optimization, gene therapy drug screening, and recipient cell line generation, using our plate reader, imaging, and electrophysiology platforms for optogenetic applications.
Do you need more information on optogenetics in clinical studies?
Learn more:
How can we support your research programs?
We offer construction of optogenetic cell lines (both with light actuators and light sensors), which can be transferred to our clients or run as part of contract research studies at Axxam, including HTS campaigns with clients’ and/or Axxam compound collections.
Moreover, we can support gene therapy drug programs, from screening of novel optogenetic tools, to functional method development and qualification, and potency assays for batch release and stability studies.