Qr: *
Showing 76 - 100 of 1894 results
76.
Advances in optogenetically engineered bacteria in disease diagnosis and therapy.
Abstract:
Optogenetic bacterial technology is a cutting-edge approach that combines optogenetics and microbiology, offering a transformative strategy for disease diagnosis and therapy. This synergistic merger transcends the limitations of traditional diagnostic and therapeutic methodologies in a highly controllable, accurate and non-invasive manner. In this review, we introduce the optogenetic systems developed for microbial engineering and summarize fundamental in vitro design principles underlying light-responsive signal transduction in bacteria, as well as the optogenetic regulation of bacterial behaviors. We address multidisciplinary solutions to the challenges in the in vivo applications of light-controlled bacteria, such as limited light excitation, suboptimal delivery and targeting, and difficulties in signal tracking and management. Furthermore, we comprehensively highlight the recent progress in photo-responsive bacteria for disease diagnosis and therapy, and discuss how to accelerate translational applications.
77.
Deep-tissue high-sensitivity multimodal imaging and optogenetic manipulation enabled by biliverdin reductase knockout.
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Kasatkina, LA
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Ma, C
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Sheng, H
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Lowerison, M
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Menozzi, L
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Baloban, M
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Tang, Y
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Xu, Y
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Humayun, L
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Vu, T
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Song, P
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Yao, J
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Verkhusha, VV
Abstract:
Performance of near-infrared probes and optogenetic tools derived from bacterial phytochromes is limited by availability of their biliverdin chromophore. To address this, we use a biliverdin reductase-A knock-out mouse model (Blvra-/-), which elevates endogenous biliverdin levels. We show that Blvra⁻/⁻ significantly enhances function of bacterial phytochrome-based systems. Light-controlled transcription using iLight optogenetic tool improves ~25-fold in Blvra-/- cells, compared to wild-type controls, and achieves ~100-fold activation in neurons. Light-induced insulin production in Blvra-/- mice reduces blood glucose by ~60% in diabetes model. To overcome depth limitations in imaging, we employ 3D photoacoustic, ultrasound, and two-photon fluorescence microscopy. This enables simultaneous photoacoustic imaging of DrBphP in neurons and super-resolution ultrasound localization microscopy of brain vasculature at depths of ~7 mm through intact scalp and skull. Two-photon microscopy achieves cellular resolution of miRFP720-expressing neurons at ~2.2 mm depth. Overall, Blvra-/- model represents powerful platform for improving efficacy of biliverdin-dependent tools for deep-tissue imaging and optogenetic manipulation.
78.
Optogenetics-enabled discovery of integrated stress response modulators.
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Wong, F
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Li, A
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Omori, S
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Lach, RS
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Nunez, J
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Ren, Y
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Brown, SP
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Singhal, V
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Lyda, BR
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Batjargal, T
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Dickson, E
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Rodrigues Reyes, JR
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Uruena Vargas, JM
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Wahane, S
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Kim, H
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Collins, JJ
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Wilson, MZ
Abstract:
The integrated stress response (ISR) is a conserved stress response that maintains homeostasis in eukaryotic cells. Modulating the ISR holds therapeutic potential for diseases including viral infection, cancer, and neurodegeneration, but few known compounds can do so without toxicity. Here, we present an optogenetic platform for the discovery of compounds that selectively modulate the ISR. Optogenetic clustering of PKR induces ISR-mediated cell death, enabling the high-throughput screening of 370,830 compounds. We identify compounds that potentiate cell death without cytotoxicity across diverse cell types and stressors. Mechanistic studies reveal that these compounds upregulate activating transcription factor 4 (ATF4), sensitizing cells to stress and apoptosis, and identify GCN2 as a molecular target. Additionally, these compounds exhibit antiviral activity, and one compound reduced viral titers in a mouse model of herpesvirus infection. Structure-activity and toxicology studies highlight opportunities to optimize therapeutic efficacy. This work demonstrates an optogenetic approach to drug discovery and introduces ISR potentiators with therapeutic potential.
79.
Traits of Bathy Phytochromes and Application to Bacterial Optogenetics.
Abstract:
Phytochromes are photoreceptors sensitive to red and far-red light, found in a wide variety of organisms, including plants, fungi, and bacteria. Bacteriophytochromes (BphPs) can be switched between a red light-sensitive Pr state and a far-red light-sensitive Pfr state by illumination. In so-called prototypical BphPs, the Pr state functions as the thermally favored resting state, whereas Pfr is more stable in bathy BphPs. The prototypical DrBphP from Deinococcus radiodurans has been shown to be compatible with different output module types. Even though red light-regulated optogenetic tools are available, like the pREDusk system based on the DrBphP photosensory module, far-red light-modulated variants are still rare. Here, we study the underlying contributors to bathy over prototypical BphP behavior by way of various chimeric constructs between pREDusk and representative bathy BphPs. We pinpoint shared traits of the otherwise heterogeneous subgroup of bathy BphPs and highlight the importance of the sensor-effector linker in light modulation of histidine kinase activity. Informed by these data, we introduce the far-red light-activated system "pFREDusk", based on a histidine kinase activity governed by a bathy photosensory module. With this tool, we expand the optogenetic toolbox into wavelengths of increased sample and tissue penetration.
80.
Capturing α-synuclein aggregation interactors using UltraID-LIPA.
Abstract:
Teixeira et al. present UltraID-light-inducible protein aggregation (UltraID-LIPA), a technique that combines optogenetic induction of α-synuclein aggregation with proximity-based proteomics. This system enables high-resolution capture of early aggregation events in live cells and implicates known and novel endolysosomal proteins, offering a robust framework for dissecting early pathogenic mechanisms in synucleinopathies and guiding future innovations.
81.
Optogenetic and chemical genetic tools for rapid repositioning of vimentin intermediate filaments.
Abstract:
Intermediate filaments (IFs) are a key component of the cytoskeleton, essential for regulating cell mechanics, maintaining nuclear integrity, organelle positioning, and modulating cell signaling. Current insights into IF function primarily come from studies using long-term perturbations, such as protein depletion or mutation. Here, we present tools that allow rapid manipulation of vimentin IFs in the whole cytoplasm or within specific subcellular regions by inducibly coupling them to microtubule motors, either pharmacologically or using light. Rapid perinuclear clustering of vimentin had no major immediate effects on the actin or microtubule organization, cell spreading, or focal adhesion number, but it reduced cell stiffness. Mitochondria and endoplasmic reticulum (ER) sheets were reorganized due to vimentin clustering, whereas lysosomes were only briefly displaced and rapidly regained their normal distribution. Keratin moved along with vimentin in some cell lines but remained intact in others. Our tools help to study the immediate and local effects of vimentin perturbation and identify direct links of vimentin to other cellular structures.
82.
Dynamin-like Proteins Combine Mechano-constriction and Membrane Remodeling to Enable Two-Step Mitochondrial Fission via a "Snap-through" Instability.
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Alimohamadi, H
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Luo, EW
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Liu, X
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Iqbal, W
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Yang, R
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Gupta, S
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Nolden, KA
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Mandal, T
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Hill, RB
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Duan, L
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Wong, GCL
Abstract:
Mitochondrial fission is controlled by dynamin-like proteins, the dysregulation of which is correlated with diverse diseases. Fission dynamin-like proteins are GTP hydrolysis-driven mechanoenzymes that self-oligomerize into helical structures that constrict membranes to achieve fission while also remodeling membranes by inducing negative Gaussian curvature, which is essential for the completion of fission. Despite advances in optical and electron imaging technologies, the underlying mechanics of mitochondrial fission remain unclear due to the multiple times involved in the dynamics of mechanoenzyme activity, oligomer disassembly, and membrane remodeling. Here, we examine how multiscale phenomena in dynamin Drp1 synergistically influence membrane fission using a mechanical model calibrated with small-angle X-ray scattering structural data and informed by a machine learning analysis of the Drp1 sequence, and tested the concept using optogenetic mechanostimulation of mitochondria in live cells. We find that free dynamin-like proteins can trigger a "snap-through instability" that enforces a shape transition from an oligomer-confined cylindrical membrane to a drastically narrower catenoid-shaped neck within the spontaneous hemi-fission regime, in a manner that depends critically on the length of the confined tube. These results indicate how the combination of assembly and paradoxically disassembly of dynamin-like proteins can lead to diverse pathways to scission.
83.
Shaping viral immunotherapy towards cancer-targeted immunological cell death.
Abstract:
Oncolytic viruses (OVs) have the ability to efficiently enter, replicate within, and destroy cancer cells. This capacity to selectively target cancer cells while inducing long-term anti-tumor immune responses, makes OVs a promising tool for next-generation cancer therapy. Immunogenic cell death (ICD) induced by OVs initiates the cancer-immunity cycle (CIC) and plays a critical role in activating and reshaping anti-cancer immunity. Genetic engineering, including arming OVs with cancer cell-specific binders and immunostimulatory molecules, further enhances immune responses at various stages of the CIC, improving the specificity and safety of virotherapy.The aim of this study is to update current knowledge in immunotherapy using OVs and to highlight the remarkable plasticity of viruses in shaping the tumor immune microenvironment, which may facilitate anti-cancer treatment through various approaches.
84.
Optogenetic storage and release of protein and mRNA in live cells and animals.
Abstract:
Cells compartmentalize biomolecules in membraneless structures called biomolecular condensates. While their roles in regulating cellular processes are increasingly understood, tools for their synthetic manipulation remain limited. Here, we introduce RELISR (Reversible Light-Induced Store and Release), an optogenetic condensate system that enables reversible storage and release of proteins or mRNAs. RELISR integrates multivalent scaffolds, optogenetic switches, and cargo-binding domains to trap cargo in the dark and release it upon blue-light exposure. We demonstrate its utility in primary neurons and show that light-triggered release of signaling proteins can modulate fibroblast morphology. Furthermore, light-induced release of cargo mRNA results in protein translation both in vitro and in live mice. RELISR thus provides a versatile platform for spatiotemporal control of protein activity and mRNA translation in complex biological systems, with broad potential for research and therapeutic applications.
85.
Optogenetic-Controlled iPSC-Based Vaccines for Prophylactic and Therapeutic Tumor Suppression in Mice.
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Qiao, L
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Niu, L
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Wang, Z
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Dai, D
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Tang, S
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Ma, X
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Deng, Z
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Yu, G
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Zhou, Y
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Yan, T
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Liu, X
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Kong, D
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Hu, L
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Li, X
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Zhao, J
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Cai, F
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Wang, M
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Ye, H
Abstract:
Induced pluripotent stem cells (iPSCs) share similar cellular features and various antigens profiles with cancer cells. Leveraging these characteristics, iPSCs hold great promise for developing wide-spectrum vaccines against cancers. In practice, iPSCs are typically combined with immune adjuvants to enhance antitumor immune responses; however, traditional adjuvants lack controllability and can induce systemic toxicity, which has limited their broad application. Here, a red/far-red light-controlled iPSC-based vaccine (RIVA) based on the chimeric photosensory protein FnBphP and its interaction partner LDB3 is developed; RIVA preserves the intrinsic tumor antigens of iPSCs and enables optogenetic control of an immune adjuvant's (IFN-β) expression under red light illumination. Experiments in multiple mouse tumor models demonstrate that RIVA inhibits tumor growth and improves animal survival in prophylactic and therapeutic settings, including against pulmonary metastatic 4T1 breast cancer. RIVA efficiently stimulates dendritic cell maturation, eliciting innate immune activation effects through NK cells and elicit adaptive immune anti-tumor responses through CD4+ and CD8+ T cells. Moreover, RIVA protects animals against tumor re-challenge by inducing strong immunological memory, with minimal systemic toxicity. This study demonstrates RIVA as an effective optogenetic approach for developing safe multi-antigen vaccines for the prevention and treatment of cancer.
86.
Engineered bacteriophytochrome heterodimers for research and applications.
Abstract:
Many proteins are dimeric, functioning as complexes of two identical or different subunits. Bacteriophytochromes are homodimeric photoreceptor proteins that sense red/far-red light with a photosensory module (PSM) and convert it to a biological response via an output module, usually a histidine kinase (HK). Here, we generate monomeric bacteriophytochrome PSMs that form stable heterodimers once mixed by modifying two salt bridges at the dimerization interface of the Deinococcus radiodurans phytochrome (DrBphP). We confirm that these heterodimeric PSMs can control output HK module activity in response to red light and reveal that dimerization is required for kinase activity of the model HK FixL, but not necessarily for phosphatase activity of DrBphP. By applying the heterodimeric variants to a red light-regulated gene expression tool, we exemplify the combined control of cellular events using both heterodimerization and light. These results pave the way for new heterodimeric systems, for example, in receptor protein research and optogenetics.
87.
Opto-p53: A light-controllable activation of p53 signaling pathway.
Abstract:
p53 protein, a crucial transcription factor in cellular responses to a wide variety of stress, regulates multiple target genes involved in tumor suppression, senescence induction, and metabolic functions. To characterize the context-dependent roles of p53, it is still needed to develop an experimental system that enables selective activation of p53 in cells and tissues. In this study, we developed an optogenetic tool, Opto-p53, to control p53 signaling by light. Opto-p53 was designed to trigger p53 signaling by reconstituting p53 N-terminal and C-terminal fragments with a light-inducible dimerization (LID) system. Upon light exposure, cells expressing Opto-p53 demonstrated p53 transcriptional activation, resulting in cell death and cell cycle arrest. We further enhanced the efficacy of light-induced p53 activation by introducing specific mutations into Opto-p53 fragments. Our findings unveil the capability of Opto-p53 to serve as a powerful tool for dissecting the complex roles of p53 in cellular processes, thereby contributing to the field of synthetic biology and providing general design principles for optogenetic tools using endogenous transcription factors.Key words: synthetic biology, transcriptional factor, p53, optogenetics.
88.
A simplified two-plasmid system for orthogonal control of mammalian gene expression using light-activated CRISPR effector.
Abstract:
Optogenetic systems use light-responsive proteins to control gene expression, ion channels, protein localization, and signaling with the "flip of a switch". One such tool is the light activated CRISPR effector (LACE) system. Its ability to regulate gene expression in a tunable, reversible, and spatially resolved manner makes it attractive for many applications. However, LACE relies on delivery of four separate components on individual plasmids, which can limit its use. Here, we optimize LACE to reduce the number of plasmids needed to deliver all four components.
89.
Optogenetic engineering of lipid droplet spatial organization for tumor suppression.
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Bai, Q
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Shao, X
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Xia, Q
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Yang, S
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Gao, Y
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Sun, K
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Li, J
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Wang, X
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Tian, Z
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Chen, X
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Zhao, J
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Diao, J
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Chen, Q
Abstract:
In cancer cells, lipid droplets (LDs) establish extensive membrane contact sites (MCSs) with mitochondria to facilitate fatty acid transfer and sustain energy production, thus enabling cancer cell survival, in nutrient-deprived tumor microenvironments. However, effective strategies to disrupt these LD-mitochondria interactions remain unavailable. We engineered an optogenetic system to control LD intracellular organization through clustering. Upon blue light stimulation, the system induces LDs to undergo spatial reorganization and form clusters, thereby restricting LD accessibility by reducing the available surface area for mitochondrial interaction. Consequently, this clustering significantly diminishes the number of LD-mitochondria MCSs, suppresses fatty acid transport from LDs to mitochondria during starvation, and ultimately leads to cancer cell death in vitro and tumor growth inhibition in vivo. Collectively, our results demonstrate that optogenetically controlled LD clustering offers a novel approach to impede tumor progression by blocking nutrient flow from LDs to mitochondria.
90.
Stimulation of corticospinal neurons by optogenetic cAMP inductions promotes motor recovery after spinal cord injury in female rats via raphespinal tract modulation.
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Martínez-Rojas, B
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Martín-Pérez, S
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Giraldo, E
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Lopez-Mocholi, E
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Alastrue, A
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Andrade-Talavera, Y
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Prius-Mengual, J
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Paniagua, G
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Pedraza, M
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Hingorani, S
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Rost, BR
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Schmitz, D
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Llansola, M
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Felipo, V
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Rodríguez-Moreno, A
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Moreno-Manzano, V
Abstract:
After spinal cord injury (SCI), cyclic adenosine monophosphate (cAMP) levels drop in the spinal cord, cortex and brainstem, unlike in regenerating peripheral neurons. To address SCI recovery, we expressed photoactivatable adenylate cyclase (bPAC) in corticospinal neurons of female rats with dorsal hemisection for on-demand cAMP inductions. bPAC stimulation restored passive and firing properties of corticospinal neurons, promoted early and sustained locomotor recovery and increased corticospinal tract plasticity. Additionally, bPAC enhanced sparing of lumbar-projecting brainstem neurons after SCI, accompanied by activation of cAMP signaling in the raphe-reticular formation and increased excitatory/inhibitory neurotransmitter balance. Accordingly, augmented density of serotonergic tracts was found caudal to the injury in bPAC rats, correlating with enhanced functional performance. Serotonergic implication in motor recovery was further evidenced by selective depletion, resulting in the abrogation of bPAC-mediated recovery. Overall, our findings underscore that cAMP induction in corticospinal neurons enhances locomotion after SCI, through a cortical rerouting pathway via the serotonergic descending tract.
91.
Pharmacological interventions on GSK3β phosphorylation-mediated tau aggregation by modulating phase separation of tau proline-rich domain.
Abstract:
Tau pathological aggregation in neurofibrillary tangles is a hallmark of several neurodegenerative diseases, including Alzheimer's disease. Phase separation is a thermodynamic process that plays an important role in biomolecular membrane-less condensate formation, while abnormal phase separation of tau leads to pathological aggregate formation. However, the detailed molecular mechanism underlying tau condensation remains not fully understood. Moreover, whether condensation-based pharmacological intervention will be helpful for the treatment of tau-associated neurodegenerative diseases remains elusive. Here, we used an optogenetic tool (optoDroplets) in combination with cell biology and pharmacology to explore the contribution of different domains for tau condensation in cells, and we found that proline-rich domain (PRD) phosphorylation, which is mainly regulated by glycogen synthase kinase 3 β (GSK3β), plays important roles for tau condensation. Moreover, phosphorylation of tau PRD regulates its mis-localization on nuclear speckle. Interestingly and importantly, we found that pharmacological inhibition of GSK3β can impede abnormal tau condensation to slow down the tau-associated pathological process.
92.
zHORSE as an optogenetic zebrafish strain for precise spatiotemporal control over gene expression during development.
Abstract:
Proper vertebrate development is dependent on tightly regulated expression of genes at the correct time and place. To identify normal but also dysregulated development leading to disease, in vivo interrogation methods with high spatiotemporal resolution are required. Recently, optogenetic tools to manipulate gene expression with spatiotemporal control have emerged, but their in vivo applications remain challenging. Here, we present a transgenic zebrafish strain termed zebrafish for heat-shock-inducible optogenetic recombinase expression (zHORSE) with inducible expression of a light-activatable Cre recombinase. We demonstrate that zHORSE endows robust spatiotemporal control over gene expression down to single-cell level at different developmental stages. We apply zHORSE for lineage tracing to identify caudal fin progenitors and for targeted expression of oncogenes. Surprisingly, one oncogene, EWS::FLI1, can cause ectopic fin formation when induced in permissive environments. zHORSE is compatible with existing loxP zebrafish effector strains and will enable many applications ranging from dissecting and precisely manipulating development to clonal cancer modeling.
93.
Programmable genome engineering and gene modifications for plant biodesign.
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Liu, J
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Zhang, R
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Chai, N
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Su, L
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Zheng, Z
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Liu, T
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Guo, Z
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Ma, Y
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Xie, Y
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Xie, X
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Lin, Q
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Chen, L
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Liu, YG
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Zhu, Q
Abstract:
Plant science has entered a transformative era as genome editing enables precise DNA modifications to address global challenges such as climate adaptation and food security. These modifications are primarily driven by the integration of three modular components-DNA-targeting modules, effector modules, and control modules-that can be selectively activated or suppressed. The field has evolved from protein-based systems (e.g., zinc finger nucleases and transcription activator-like effector nucleases) to RNA-guided systems (e.g., CRISPR-Cas) that can control both genetic and epigenetic states. Modular pairing of DNA-targeting and effector domains, with or without inducible control, enables precise transcriptional regulation and chromatin remodeling. The present review examines these three modules and highlights strategies for their optimization. It also outlines innovative tools, such as optogenetic and receptor-integrated systems, that enable spatiotemporal control over genome editor expression. These modular approaches bypass traditional limitations and allow scientists to create plants with desirable traits, decipher complex gene networks, and promote sustainable agriculture.
94.
Optogenetics to biomolecular phase separation in neurodegenerative diseases.
Abstract:
Neurodegenerative diseases involve toxic protein aggregation. Recent evidence suggests that biomolecular phase separation, a process in which proteins and nucleic acids form dynamic, liquid-like condensates, plays a key role in this aggregation. Optogenetics, originally developed to control neuronal activity with light, has emerged as a powerful tool to investigate phase separation in living systems. This is achieved by fusing disease-associated proteins to light-sensitive oligomerization domains, enabling researchers to induce or reverse condensate formation with precise spatial and temporal control. This review highlights how optogenetic systems such as OptoDroplet are being used to dissect the mechanisms of neurodegenerative disease. We examine how these tools have been applied in models of neurodegenerative diseases, such as amyotrophic lateral sclerosis, Alzheimer's, Parkinson's, and Huntington's disease. These studies implicate small oligomeric aggregates as key drivers of toxicity and highlight new opportunities for therapeutic screening. Finally, we discuss advances in light-controlled dissolution of condensates and future directions for applying optogenetics to combat neurodegeneration. By enabling precise, dynamic control of protein phase behavior in living systems, optogenetic approaches provide a powerful framework for elucidating disease mechanisms and informing the development of targeted therapies.
95.
Optogenetic perturbation of lipid droplet localization affects lipid metabolism and development in Drosophila.
Abstract:
Lipid droplets (LDs) are dynamic organelles crucial for lipid storage and homeostasis. Despite extensive documentation of their importance, the causal relationship between LD localization and function in health and disease remains inadequately understood. Here, we developed optogenetics-based tools, termed "Opto-LDs," which facilitate the interaction between LDs and motor proteins in a light-dependent manner, enabling precise control of LD localization within cells. Utilizing these optogenetic modules, we demonstrated that light-induced relocation of LDs to the periphery of hepatocytes results in elevated very-low-density lipoprotein (VLDL) secretion, recapturing the beneficial effect of insulin in vitro. Furthermore, our studies in transgenic Drosophila revealed that proper LD localization is critical for embryonic development, with mistargeting of LDs significantly affecting egg hatching success. In summary, our work underscores the great importance of LD localization in lipid metabolism and development, and our developed tools offer valuable insights into the functions of LDs in health and disease.
96.
Potent optogenetic regulation of gene expression in mammalian cells for bioproduction and basic research.
Abstract:
Precise temporal and spatial control of gene expression greatly benefits the study of specific cellular circuits and activities. Compared to chemical inducers, light-dependent control of gene expression by optogenetics achieves a higher spatial and temporal resolution. Beyond basic research, this could also prove decisive for manufacturing difficult-to-express proteins in pharmaceutical bioproduction. However, current optogenetic gene-expression systems limit this application in mammalian cells, as expression levels and the degree of induction upon light stimulation are insufficient. To overcome this limitation, we designed a photoswitch by fusing the blue light-activated light-oxygen-voltage receptor EL222 from Erythrobacter litoralis to the three transcriptional activator domains VP64, p65, and Rta in tandem. The resultant photoswitch, dubbed DEL-VPR, allows up to a 570-fold induction of target gene expression by blue light, thereby achieving expression levels of strong constitutive promoters. Here, we used DEL-VPR to enable light-induced expression of complex monoclonal and bispecific antibodies with reduced byproduct expression and increased yield of functional protein complexes. Our approach offers temporally controlled yet strong gene expression and applies to academic and industrial settings.
97.
RhoA activation promotes ordered membrane domain coalescence and suppresses neuronal excitability.
Abstract:
This study explores how the small GTPase RhoA modulates plasma membrane lipid nanodomains, particularly cholesterol-rich ordered membrane domains (OMDs). These nanodomains play a critical role in regulating ion channel activity and neuronal excitability. However, due to their nanoscale dimensions, OMDs remain challenging to visualize using conventional light microscopy. Here, we used fluorescently labeled cholera toxin B (CTxB) and the palmitoylated peptide Lck-10 (L10) as probes to visualize OMDs and quantified their size via confocal fluorescence lifetime imaging microscopy (FLIM)-based Förster resonance energy transfer (FRET). Pharmacological inhibition of RhoA significantly reduced OMD sizes in both human cell lines and dorsal root ganglion (DRG) neurons. To achieve better spatiotemporal control of specific RhoA activation, we employed an improved light-inducible dimerization (iLID) system. Optogenetic activation of RhoA rapidly increased FRET efficiency between CTxB probes, indicating OMD coalescence. Functionally, RhoA inhibition potentiated hyperpolarization-activated cyclic nucleotide-gated (HCN) channel activity in nociceptive DRG neurons, increasing spontaneous action potential firing. Conversely, in a spared nerve injury rat model, RhoA activation expanded OMDs in nociceptive DRG neurons. Constitutive RhoA activation suppressed HCN channel activity and decreased membrane excitability. These findings support a neuroprotective role for RhoA activation, where it restores OMD size and suppresses pathological hyperexcitability in neuropathic pain.
98.
An Optical Approach to Modulating Membrane Protein Endocytosis Using a Light-Responsive Tag for Recruiting β-Arrestin.
Abstract:
Membrane receptors, particularly G protein-coupled receptors (GPCRs), are integral to numerous physiological processes. Precise control of the receptor endocytosis is essential for understanding cellular signaling pathways. In this study, we present the development of a broadly applicable optogenetic tool for light-inducible receptor internalization. This system, named E-fragment, leverages the CRY2-CIB photodimerization pair to enable blue-light-dependent recruitment of β-arrestin and subsequent receptor internalization. We showed that the E-fragment system is applicable across diverse membrane proteins, including multiple GPCRs. Furthermore, we investigated its impact on intracellular cAMP signaling in cells expressing dopamine receptor D1 and α2-adrenergic receptor. Quantitative analyses revealed that light-induced internalization led to reduced surface receptor expression and attenuated ligand-evoked cAMP responses. These findings demonstrate the versatility of the E-fragment system as a platform for studying membrane receptor function and suggest potential applications in therapeutic strategies targeting receptor trafficking and signaling modulation.
99.
Improving the Response of Microbial Fuel Cell-Based Biosensing through Optogenetic Enhancement of Electroactive Biofilms.
Abstract:
Early detection of pollutants in water discharge is an integral part of environmental monitoring. Electroactive biofilm (EAB)-enabled, microbial fuel cell (MFC)-based biosensors facilitate self-powered online pollutant detection. However, as EABs are highly dynamic, naturally formed EABs as sensing and transducing elements limit the performance of MFC-based biosensors. Here, we report a fast-response and sensitive MFC-based biosensor enabled by enhancing Shewanella oneidensis biofilms on the electrode using an optogenetic approach. We incorporated a near-infrared (NIR) light-responsive synthetic bis(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) module into S. oneidensis to promote biofilm formation on the anode under NIR light. The biosensors with enhanced EABs exhibited a rapid and sensitive response to Cr(VI), reducing the sensing time from approximately 30 min to just 3 min. This improved sensing performance was maintained over three sensing cycles, even with fluctuating Cr(VI) concentrations. Based on the analyses of the electrode biofilms and extracellular polymeric substance matrices, different Cr(VI) response mechanisms for the normal and enhanced EABs were proposed; enhanced EAB's massive dispersal by Cr(VI) was the cause of the improved response of the biosensors. Such improved response still held in the natural water matrix. This proof-of-concept study provides valuable insights into controlling electrode biofilm dynamics for the rapid and robust early detection of pollutants using MFC-based biosensors.
100.
Orthogonal replication with optogenetic selection evolves yeast JEN1 into a mevalonate transporter.
Abstract:
The in vivo continuous evolution system OrthoRep (orthogonal replication) is a powerful strategy for rapid enzyme evolution in Saccharomyces cerevisiae that diversifies genes at a rate exceeding the endogenous genome mutagenesis rate by several orders of magnitude. However, it is difficult to neofunctionalize genes using OrthoRep partly because of the way selection pressures are applied. Here we combine OrthoRep with optogenetics in a selection strategy we call OptoRep, which allows fine-tuning of selection pressure with light. With this capability, we evolved a truncated form of the endogenous monocarboxylate transporter JEN1 (JEN1t) into a de novo mevalonate importer. We demonstrate the functionality of the evolved JEN1t (JEN1tY180C/G) in the production of farnesene, a renewable aviation biofuel, from mevalonate fed to fermentation media or produced by microbial consortia. This study shows that the light-induced complementation of OptoRep may improve the ability to evolve functions not currently accessible for selection, while its fine tunability of selection pressure may allow the continuous evolution of genes whose desired function has a restrictive range between providing effective selection and cellular viability.
