Ultrasound Control of Gene Expression in Human iPSCs via Heat Shock Promoters.

Inducible systems are crucial tools in biomedical research, offering researchers spatiotemporal control at the cellular level. A promising development in this field is the use of focused ultrasound for controlling gene expression using heat shock promoters (HSPs). Focused ultrasound-induced mild hyperthermia activates the cellular heat shock response, which in turn activates HSPs and subsequently drives gene expression.

Hypoimmunogenic hPSC-derived cardiac organoids for immune evasion and heart repair.

Human pluripotent stem cell (hPSC)-derived cardiac therapies hold great promise for heart regeneration but face major translational barriers due to allogeneic immune rejection. Here, we engineered hypoimmunogenic hPSCs using a two-step CRISPR-Cas9 strategy: (1) B2M knockout, eliminating HLA class I surface expression, and (2) knock-in of HLA-E or HLA-G trimer constructs in the AAVS1 safe harbor locus to confer robust immune evasion. Hypoimmunogenic hPSCs maintained pluripotency, efficiently differentiated into cardiac cell types that resisted both T and NK cell-mediated cytotoxicity , and self-assembled into engineered cardiac organoids.

Gas Vesicle-Expressing Human Pluripotent Stem Cells Enable Multimodal Ultrasound and Optical Coherence Tomographic Imaging.

Genetically encoded imaging reporters are critical tools for tracking cell fate and function in regenerative medicine. Gas vesicles (GVs), air-filled protein nanostructures derived from bacteria, offer unique advantages for noninvasive imaging due to their acoustic and optical properties. In this study, we engineered human pluripotent stem cells (hPSCs) to express GVs using a doxycycline-inducible system.

A drug-selectable acoustic reporter gene system for human cell ultrasound imaging.

A promising new field of genetically encoded ultrasound contrast agents in the form of gas vesicles has recently emerged, which could extend the specificity of medical ultrasound imaging. However, given the delicate genetic nature of how these genes are integrated and expressed, current methods of producing gas vesicle-expressing mammalian cell lines requires significant cell processing time to establish a clonal/polyclonal line that robustly expresses the gas vesicles sufficiently enough for ultrasound contrast. Here, we describe an inducible and drug-selectable acoustic reporter gene system that can enable gas vesicle expression in mammalian cell lines, which we demonstrate using HEK293T cells.