Ching Ting Tsai

All Publications

• Actin-driven nanotopography promotes stable integrin adhesion formation in developing tissue. Nature communications Chen, T., Fernández-Espartero, C. H., Illand, A., Tsai, C. T., Yang, Y., Klapholz, B., Jouchet, P., Fabre, M., Rossier, O., Cui, B., Lévêque-Fort, S., Brown, N. H., Giannone, G. 2024; 15 (1): 8691

  Abstract

  Morphogenesis requires building stable macromolecular structures from highly dynamic proteins. Muscles are anchored by long-lasting integrin adhesions to resist contractile force. However, the mechanisms governing integrin diffusion, immobilization, and activation within developing tissues remain elusive. Here, we show that actin polymerization-driven membrane protrusions form nanotopographies that enable strong adhesion at Drosophila muscle attachment sites (MASs). Super-resolution microscopy reveals that integrins assemble adhesive belts around Arp2/3-dependent actin protrusions, forming invadosome-like structures with membrane nanotopographies. Single protein tracking shows that, during MAS development, integrins become immobile and confined within diffusion traps formed by the membrane nanotopographies. Actin filaments also display restricted motion and confinement, indicating strong mechanical connection with integrins. Using isolated muscle cells, we show that substrate nanotopography, rather than rigidity, drives adhesion maturation by regulating actin protrusion, integrin diffusion and immobilization. These results thus demonstrate that actin-polymerization-driven membrane protrusions are essential for the formation of strong integrin adhesions sites in the developing embryo, and highlight the important contribution of geometry to morphogenesis.

  View details for DOI 10.1038/s41467-024-52899-x

  View details for PubMedID 39375335

  View details for PubMedCentralID PMC11458790

• Plasma membrane curvature regulates the formation of contacts with the endoplasmic reticulum. Nature cell biology Yang, Y., Valencia, L. A., Lu, C. H., Nakamoto, M. L., Tsai, C. T., Liu, C., Yang, H., Zhang, W., Jahed, Z., Lee, W. R., Santoro, F., Liou, J., Wu, J. C., Cui, B. 2024

  Abstract

  Contact sites between the endoplasmic reticulum (ER) and plasma membrane (PM) play a crucial role in governing calcium regulation and lipid homeostasis. Despite their significance, the factors regulating their spatial distribution on the PM remain elusive. Inspired by observations in cardiomyocytes, where ER-PM contact sites concentrate on tubular PM invaginations known as transverse tubules, we hypothesize that PM curvature plays a role in ER-PM contact formation. Through precise control of PM invaginations, we show that PM curvatures locally induce the formation of ER-PM contacts in cardiomyocytes. Intriguingly, the junctophilin family of ER-PM tethering proteins, specifically expressed in excitable cells, is the key player in this process, whereas the ubiquitously expressed extended synaptotagmin-2 does not show a preference for PM curvature. At the mechanistic level, we find that the low-complexity region (LCR) and membrane occupation and recognition nexus (MORN) motifs of junctophilins can bind independently to the PM, but both the LCR and MORN motifs are required for targeting PM curvatures. By examining the junctophilin interactome, we identify a family of curvature-sensing proteins-Eps15 homology domain-containing proteins-that interact with the MORN_LCR motifs and facilitate the preferential tethering of junctophilins to curved PM. These findings highlight the pivotal role of PM curvature in the formation of ER-PM contacts in cardiomyocytes and unveil a mechanism for the spatial regulation of ER-PM contacts through PM curvature modulation.

  View details for DOI 10.1038/s41556-024-01511-x

  View details for PubMedID 39289582

  View details for PubMedCentralID 6427007

• Engineering the Cellular Microenvironment: Integrating Three-Dimensional Nontopographical and Two-Dimensional Biochemical Cues for Precise Control of Cellular Behavior. ACS nano Sarikhani, E., Meganathan, D. P., Larsen, A. K., Rahmani, K., Tsai, C. T., Lu, C. H., Marquez-Serrano, A., Sadr, L., Li, X., Dong, M., Santoro, F., Cui, B., Klausen, L. H., Jahed, Z. 2024

  Abstract

  The development of biomaterials capable of regulating cellular processes and guiding cell fate decisions has broad implications in tissue engineering, regenerative medicine, and cell-based assays for drug development and disease modeling. Recent studies have shown that three-dimensional (3D) nanoscale physical cues such as nanotopography can modulate various cellular processes like adhesion and endocytosis by inducing nanoscale curvature on the plasma and nuclear membranes. Two-dimensional (2D) biochemical cues such as protein micropatterns can also regulate cell function and fate by controlling cellular geometries. Development of biomaterials with precise control over nanoscale physical and biochemical cues can significantly influence programming cell function and fate. In this study, we utilized a laser-assisted micropatterning technique to manipulate the 2D architectures of cells on 3D nanopillar platforms. We performed a comprehensive analysis of cellular and nuclear morphology and deformation on both nanopillar and flat substrates. Our findings demonstrate the precise engineering of single cell architectures through 2D micropatterning on nanopillar platforms. We show that the coupling between the nuclear and cell shape is disrupted on nanopillar surfaces compared to flat surfaces. Furthermore, our results suggest that cell elongation on nanopillars enhances nanopillar-induced endocytosis. We believe our platform serves as a versatile tool for further explorations into programming cell function and fate through combined physical cues that create nanoscale curvature on cell membranes and biochemical cues that control the geometry of the cell.

  View details for DOI 10.1021/acsnano.4c03743

  View details for PubMedID 38978500

• Membrane Curvature Promotes ER-PM Contact Formation via Junctophilin-EHD Interactions. bioRxiv : the preprint server for biology Yang, Y., Valencia, L. A., Lu, C. H., Nakamoto, M. L., Tsai, C. T., Liu, C., Yang, H., Zhang, W., Jahed, Z., Lee, W. R., Santoro, F., Liou, J., Wu, J. C., Cui, B. 2024

  Abstract

  Contact sites between the endoplasmic reticulum (ER) and the plasma membrane (PM) play a crucial role in governing calcium regulation and lipid homeostasis. Despite their significance, the factors regulating their spatial distribution on the PM remain elusive. Inspired by observations in cardiomyocytes, where ER-PM contact sites concentrate on tubular PM invaginations known as transverse tubules (T-tubules), we hypothesize that the PM curvature plays a role in ER-PM contact formation. Through precise control of PM invaginations, we show that PM curvatures locally induce the formation of ER-PM contacts in cardiomyocytes. Intriguingly, the junctophilin family of ER-PM tethering proteins, specifically expressed in excitable cells, is the key player in this process, while the ubiquitously expressed extended synaptotagmin 2 does not show a preference for PM curvature. At the mechanistic level, we find that the low complexity region (LCR) and the MORN motifs of junctophilins can independently bind to the PM, but both the LCR and MORN motifs are required for targeting PM curvatures. By examining the junctophilin interactome, we identify a family of curvature-sensing proteins, Eps15-homology domain containing proteins (EHDs), that interact with the MORN_LCR motifs and facilitate junctophilins' preferential tethering to curved PM. These findings highlight the pivotal role of PM curvature in the formation of ER-PM contacts in cardiomyocytes and unveil a novel mechanism for the spatial regulation of ER-PM contacts through PM curvature modulation.

  View details for DOI 10.1101/2024.06.29.601287

  View details for PubMedID 38979311

  View details for PubMedCentralID PMC11230412

• Kirigami electronics for long-term electrophysiological recording of human neural organoids and assembloids. Nature biotechnology Yang, X., Forro, C., Li, T. L., Miura, Y., Zaluska, T. J., Tsai, C., Kanton, S., McQueen, J. P., Chen, X., Mollo, V., Santoro, F., Pașca, S. P., Cui, B. 2024

  Abstract

  Realizing the full potential of organoids and assembloids to model neural development and disease will require improved methods for long-term, minimally invasive recording of electrical activity. Current technologies, such as patch clamp, penetrating microelectrodes, planar electrode arrays and substrate-attached flexible electrodes, do not allow chronic recording of organoids in suspension, which is necessary to preserve architecture. Inspired by kirigami art, we developed flexible electronics that transition from a two-dimensional to a three-dimensional basket-like configuration with either spiral or honeycomb patterns to accommodate the long-term culture of organoids in suspension. Here we show that this platform, named kirigami electronics (KiriE), integrates with and enables chronic recording of cortical organoids for up to 120days while preserving their morphology, cytoarchitecture and cell composition. We demonstrate integration of KiriE with optogenetic and pharmacological manipulation and modeling phenotypes related to a genetic disease. Moreover, KiriE can capture corticostriatal connectivity in assembloids following optogenetic stimulation. Thus, KiriE will enable investigation of disease and activity patterns underlying nervous system assembly.

  View details for DOI 10.1038/s41587-023-02081-3

  View details for PubMedID 38253880

• Curved adhesions mediate cell attachment to soft matrix fibres in three dimensions. Nature cell biology Zhang, W., Lu, C. H., Nakamoto, M. L., Tsai, C. T., Roy, A. R., Lee, C. E., Yang, Y., Jahed, Z., Li, X., Cui, B. 2023

  Abstract

  Integrin-mediated focal adhesions are the primary architectures that transmit forces between the extracellular matrix (ECM) and the actin cytoskeleton. Although focal adhesions are abundant on rigid and flat substrates that support high mechanical tensions, they are sparse in soft three-dimensional (3D) environments. Here we report curvature-dependent integrin-mediated adhesions called curved adhesions. Their formation is regulated by the membrane curvatures imposed by the topography of ECM protein fibres. Curved adhesions are mediated by integrin ɑvβ5 and are molecularly distinct from focal adhesions and clathrin lattices. The molecular mechanism involves a previously unknown interaction between integrin β5 and a curvature-sensing protein, FCHo2. We find that curved adhesions are prevalent in physiological conditions, and disruption of curved adhesions inhibits the migration of some cancer cell lines in 3D fibre matrices. These findings provide a mechanism for cell anchorage to natural protein fibres and suggest that curved adhesions may serve as a potential therapeutic target.

  View details for DOI 10.1038/s41556-023-01238-1

  View details for PubMedID 37770566

  View details for PubMedCentralID 6449687

• A NanoCurvS platform for quantitative and multiplex analysis of curvature-sensing proteins. Biomaterials science Lu, C. H., Tsai, C. T., Jones Iv, T., Chim, V., Klausen, L. H., Zhang, W., Li, X., Jahed, Z., Cui, B. 2023

  Abstract

  The cell membrane is characterized by a rich variety of topographical features such as local protrusions or invaginations. Curvature-sensing proteins, including the Bin/Amphiphysin/Rvs (BAR) or epsin N-terminal homology (ENTH) family proteins, sense the bending sharpness and the positive/negative sign of these topographical features to induce subsequent intracellular signaling. A number of assays have been developed to study curvature-sensing properties of proteins in vitro, but it is still challenging to probe low curvature regime with the diameter of curvature from hundreds of nanometers to micrometers. It is particularly difficult to generate negative membrane curvatures with well-defined curvature values in the low curvature regime. In this work, we develop a nanostructure-based curvature sensing (NanoCurvS) platform that enables quantitative and multiplex analysis of curvature-sensitive proteins in the low curvature regime, in both negative and positive directions. We use NanoCurvS to quantitatively measure the sensing range of a negative curvature-sensing protein IRSp53 (an I-BAR protein) and a positive curvature-sensing protein FBP17 (an F-BAR protein). We find that, in cell lysates, the I-BAR domain of IRSp53 is able to sense shallow negative curvatures with the diameter-of-curvature up to 1500 nm, a range much wider than previously expected. NanoCurvS is also used to probe the autoinhibition effect of IRSp53 and the phosphorylation effect of FBP17. Therefore, the NanoCurvS platform provides a robust, multiplex, and easy-to-use tool for quantitative analysis of both positive and negative curvature-sensing proteins.

  View details for DOI 10.1039/d2bm01856j

  View details for PubMedID 37337788

• Engineering cell morphology using maskless 2D protein micropatterning on 3D nanostructures Sarikhani, E., Klausen, L., Meganathan, D., Serrano, A., Tsai, C., Cui, B., Jahed, Z. CELL PRESS. 2023: 553A

  View details for Web of Science ID 000989629703067

• Modulation of nuclear membrane repair machinery by nano-needle arrays. Biophysical journal Hosseini, R., Shukla, S., Sarikhani, E., Meganathan, D., Badle, R., Spain, L., Okerblom, J., Tsai, C., Cui, B., Jahed, Z. 2023; 122 (3S1): 552a

  View details for DOI 10.1016/j.bpj.2022.11.2922

  View details for PubMedID 36784865

• A versatile nanoelectrode platform for electrical recording of diverse cell types. Biophysical journal Shukla, S. R., Tsai, C., Jahed, Z., Cui, B. 2023; 122 (3S1): 431a

  View details for DOI 10.1016/j.bpj.2022.11.2333

  View details for PubMedID 36784209

• Engineering cell morphology using maskless 2D protein micropatterning on 3D nanostructures. Biophysical journal Sarikhani, E., Klausen, L., Pushpa Meganathan, D., Marquez Serrano, A., Tsai, C., Cui, B., Jahed, Z. 2023; 122 (3S1): 553a

  View details for DOI 10.1016/j.bpj.2022.11.2925

  View details for PubMedID 36784871

• Expansion microscopy for imaging the cell-material interface. Biophysical journal Nakamoto, M. L., Forro, C., Zhang, W., Tsai, C., Cui, B. 2023; 122 (3S1): 133a

  View details for DOI 10.1016/j.bpj.2022.11.883

  View details for PubMedID 36782597

• Expansion microscopy for imaging the cell-material interface Nakamoto, M. L., Forro, C., Zhang, W., Tsai, C., Cui, B. CELL PRESS. 2023: 133A

  View details for Web of Science ID 000989629700646

• Modulation of nuclear membrane repair machinery by nano-needle arrays Hosseini, R., Shukla, S., Sarikhani, E., Meganathan, D., Badle, R., Spain, L., Okerblom, J., Tsai, C., Cui, B., Jahed, Z. CELL PRESS. 2023: 552A

  View details for Web of Science ID 000989629703064

• A versatile nanoelectrode platform for electrical recording of diverse cell types Shukla, S. R., Tsai, C., Jahed, Z., Cui, B. CELL PRESS. 2023: 431A

  View details for Web of Science ID 000989629702346

• A NanoCurvS platform for quantitative and multiplex analysis of curvature-sensing proteins Biomaterials Science Lu, C., et al 2023

  View details for DOI 10.1039/D2BM01856J

• Quantitative phase contrast imaging with a nonlocal angle-selective metasurface. Nature communications Ji, A., Song, J. H., Li, Q., Xu, F., Tsai, C. T., Tiberio, R. C., Cui, B., Lalanne, P., Kik, P. G., Miller, D. A., Brongersma, M. L. 2022; 13 (1): 7848

  Abstract

  Phase contrast microscopy has played a central role in the development of modern biology, geology, and nanotechnology. It can visualize the structure of translucent objects that remains hidden in regular optical microscopes. The optical layout of a phase contrast microscope is based on a 4 f image processing setup and has essentially remained unchanged since its invention by Zernike in the early 1930s. Here, we propose a conceptually new approach to phase contrast imaging that harnesses the non-local optical response of a guided-mode-resonator metasurface. We highlight its benefits and demonstrate the imaging of various phase objects, including biological cells, polymeric nanostructures, and transparent metasurfaces. Our results showcase that the addition of this non-local metasurface to a conventional microscope enables quantitative phase contrast imaging with a 0.02π phase accuracy. At a high level, this work adds to the growing body of research aimed at the use of metasurfaces for analog optical computing.

  View details for DOI 10.1038/s41467-022-34197-6

  View details for PubMedID 36543788

  View details for PubMedCentralID PMC9772391

• Cardiotoxicity drug screening based on whole-panel intracellular recording. Biosensors & bioelectronics Yang, Y., Liu, A., Tsai, C., Liu, C., Wu, J. C., Cui, B. 2022; 216: 114617

  Abstract

  Unintended binding of small-molecule drugs to ion channels affects electrophysiological properties of cardiomyocytes and potentially leads to arrhythmia and heart failure. The waveforms of intracellular action potentials reflect the coordinated activities of cardiac ion channels and serve as a reliable means for assessing drug toxicity, but the implementation is limited by the low throughput of patch clamp for intracellular recording measurements. In the last decade, several new technologies are being developed to address this challenge. We recently developed the nanocrown electrode array (NcEA) technology that allows robust, parallel, and long-duration recording of intracellular action potentials (iAPs). Here, we demonstrate that NcEAs allow comparison of iAP waveforms before and after drug treatment from the same cell. This self-referencing comparison not only shows distinct drug effects of sodium, potassium, and calcium blockers, but also reveals subtle differences among three subclasses of sodium channel blockers with sub-millisecond accuracy. Furthermore, self-referencing comparison unveils heterogeneous drug responses among different cells. In our study, whole-panel simultaneous intracellular recording can be reliably achieved with 94% success rate. The average duration of intracellular recording is 30min and some last longer than 2h. With its high reliability, long recording duration, and easy-to-use nature, NcEA would be useful for iAP-based preclinical drug screening.

  View details for DOI 10.1016/j.bios.2022.114617

  View details for PubMedID 36027802

• Expansion Microscopy for Imaging the Cell-Material Interface. ACS nano Nakamoto, M. L., Forro, C., Zhang, W., Tsai, C., Cui, B. 2022

  Abstract

  Surface topography on the scale of tens of nanometers to several micrometers substantially affects cell adhesion, migration, and differentiation. Recent studies using electron microscopy and super-resolution microscopy provide insight into how cells interact with surface nanotopography; however, the complex sample preparation and expensive imaging equipment required for these methods makes them not easily accessible. Expansion microscopy (ExM) is an affordable approach to image beyond the diffraction limit, but ExM cannot be readily applied to image the cell-material interface as most materials do not expand. Here, we develop a protocol that allows the use of ExM to resolve the cell-material interface with high resolution. We apply the technique to image the interface between U2OS cells and nanostructured substrates as well as the interface between primary osteoblasts with titanium dental implants. The high spatial resolution enabled by ExM reveals that although AP2 and F-actin both accumulate at curved membranes induced by vertical nanostructures, they are spatially segregated. Using ExM, we also reliably image how osteoblasts interact with roughened titanium implant surfaces below the diffraction limit; this is of great interest to understand osseointegration of the implants but has up to now been a significant technical challenge due to the irregular shape, the large volume, and the opacity of the titanium implants that have rendered them incompatible with other super-resolution techniques. We believe that our protocol will enable the use of ExM as a powerful tool for cell-material interface studies.

  View details for DOI 10.1021/acsnano.1c11015

  View details for PubMedID 35533401

• Nanocrown electrodes for parallel and robust intracellular recording of cardiomyocytes. Nature communications Jahed, Z., Yang, Y., Tsai, C., Foster, E. P., McGuire, A. F., Yang, H., Liu, A., Forro, C., Yan, Z., Jiang, X., Zhao, M., Zhang, W., Li, X., Li, T., Pawlosky, A., Wu, J. C., Cui, B. 2022; 13 (1): 2253

  Abstract

  Drug-induced cardiotoxicity arises primarily when a compound alters the electrophysiological properties of cardiomyocytes. Features of intracellular action potentials (iAPs) are powerful biomarkers that predict proarrhythmic risks. In the last decade, a number of vertical nanoelectrodes have been demonstrated to achieve parallel and minimally-invasive iAP recordings. However, the large variability in success rate and signal strength have hindered nanoelectrodes from being broadly adopted for proarrhythmia drug assessment. In this work, we develop vertically-aligned nanocrown electrodes that are mechanically robust and achieve>99% success rates in obtaining intracellular access through electroporation. We validate the accuracy of nanocrown electrode recordings by simultaneous patch clamp recording from the same cell. Finally, we demonstrate that nanocrown electrodes enable prolonged iAP recording for continual monitoring of the same cells upon the sequential addition of four incremental drug doses. Our technology development provides an advancement towards establishing an iAP screening assay for preclinical evaluation of drug-induced arrhythmogenicity.

  View details for DOI 10.1038/s41467-022-29726-2

  View details for PubMedID 35474069

• Exploring cell-surface nanopillar interactions with 3D superresolution microscopy Roy, A. R., Zhang, W., Jahed, Z., Tsai, C., Cui, B., Moerner, W. E. CELL PRESS. 2022: 278A

  View details for Web of Science ID 000759523001617

• Intracellular recording of cardiac action potentials via membrane electroporation Cui, B., Jahed, Z., Yang, Y., Tsai, C. CELL PRESS. 2022: 304A

  View details for Web of Science ID 000759523002022

• Mesh electrode arrays for integration with electrogenic organoids Forro, C., Li, T., Yang, X., Tsai, C., Cui, B., Pasca, S. CELL PRESS. 2022: 16

  View details for Web of Science ID 000759523000078

• Membrane curvature regulates the spatial distribution of bulky glycoproteins NATURE COMMUNICATIONS Lu, C., Pedram, K., Tsai, C., Jones IV, T., Li, X., Nakamoto, M. L., Bertozzi, C. R., Cui, B. 2022; 13

  View details for DOI 10.1038/s41467-022-30610-2

• Nanoscale Surface Topography Reduces Focal Adhesions and Cell Stiffness by Enhancing Integrin Endocytosis. Nano letters Li, X., Klausen, L. H., Zhang, W., Jahed, Z., Tsai, C., Li, T. L., Cui, B. 2021

  Abstract

  Both substrate stiffness and surface topography regulate cell behavior through mechanotransduction signaling pathways. Such intertwined effects suggest that engineered surface topographies might substitute or cancel the effects of substrate stiffness in biomedical applications. However, the mechanisms by which cells recognize topographical features are not fully understood. Here we demonstrate that the presence of nanotopography drastically alters cell behavior such that neurons and stem cells cultured on rigid glass substrates behave as if they were on soft hydrogels. With atomic force microscopy, we show that rigid nanotopography resembles the effects of soft hydrogels in reducing cell stiffness and membrane tension. Further, we reveal that nanotopography reduces focal adhesions and cell stiffness by enhancing the endocytosis and the subsequent removal of integrin receptors. This mechanistic understanding will support the rational design of nanotopography that directs cells on rigid materials to behave as if they were on soft ones.

  View details for DOI 10.1021/acs.nanolett.1c01934

  View details for PubMedID 34346220

• Exploring Cell Surface-Nanopillar Interactions with 3D Super-Resolution Microscopy. ACS nano Roy, A. R., Zhang, W., Jahed, Z., Tsai, C. T., Cui, B., Moerner, W. E. 2021

  Abstract

  Plasma membrane topography has been shown to strongly influence the behavior of many cellular processes such as clathrin-mediated endocytosis, actin rearrangements, and others. Recent studies have used three-dimensional (3D) nanostructures such as nanopillars to imprint well-defined membrane curvatures (the "nano-bio interface"). In these studies, proteins and their interactions were probed by two-dimensional fluorescence microscopy. However, the low resolution and limited axial detail of such methods are not optimal to determine the relative spatial position and distribution of proteins along a 100 nm-diameter object, which is below the optical diffraction limit. Here, we introduce a general method to explore the nanoscale distribution of proteins at the nano-bio interface with 10-20 nm precision using 3D single-molecule super-resolution (SR) localization microscopy. This is achieved by combining a silicone-oil immersion objective and 3D double-helix point spread function microscopy. We carefully adjust the objective to minimize spherical aberrations between quartz nanopillars and the cell. To validate the 3D SR method, we imaged the 3D shape of surface-labeled nanopillars and compared the results with electron microscopy measurements. Turning to transmembrane-anchored labels in cells, the high quality 3D SR reconstructions reveal the membrane tightly wrapping around the nanopillars. Interestingly, the cytoplasmic protein AP-2 involved in clathrin-mediated endocytosis accumulates along the nanopillar above a specific threshold of 1/R (the reciprocal of the radius) membrane curvature. Finally, we observe that AP-2 and actin preferentially accumulate at positive Gaussian curvature near the pillar caps. Our results establish a general method to investigate the nanoscale distribution of proteins at the nano-bio interface using 3D SR microscopy.

  View details for DOI 10.1021/acsnano.1c05313

  View details for PubMedID 34582687

• Quantitative Nano-Platforms for Interrogation of Curvature Sensitive Proteins Tsai, C. CELL PRESS. 2020: 249A–250A

  View details for Web of Science ID 000513023201503