Biology subjects

Chen, X.-Z.

Publications and source records attributed to Chen, X.-Z..

6 recordsLinked to original sources

bioRxiv2026

Dynamic Nanoparticle Assembly-Based Biomedical Microrobots

Precise drug delivery within anatomically complex tissues demands systems capable of both active navigation and deep tissue access, properties that have remained difficult to reconcile in existing nanocarriers and microrobots. Here we introduce Dynabots, a dynamic microrobotic assembly constructed from multifunctional nanoparticles covalently linked by thermally cleavable molecular connectors. This nanoparticle-rich architecture enables the integration of magnetic, imaging, and therapeutic components while preserving a high content of functional material. Collective assembly imparts enhanced magnetic responsiveness and maneuverability, enabling controlled navigation through tortuous biological environments. Upon exposure to mild thermal stimuli, the assemblies undergo programmed disassembly, releasing individual nanoparticles that can diffuse through tissue for localized therapeutic action. We establish the programmable transitions, biocompatibility, and therapeutic efficacy of this process across in vitro and in vivo models, including real-time fluoroscopic guidance within anatomically realistic phantoms and live rodent and porcine systems. By integrating magnetic control, reconfigurable architecture, and stimulus-triggered disassembly, Dynabots unite navigational precision with tissue permeability, providing a versatile platform for adaptive and deep-tissue drug delivery.

bioengineering↗

bioRxiv2026

Mechanical confinement drives monocyte-to-macrophage differentiation

Cells in vivo experience mechanically diverse microenvironments in which physical confinement is a pervasive but poorly understood regulator of their behavior and fate. Whether and how mechanical confinement governs immune cell differentiation remains unknown. Here, we reveal that a mechanical cue -- long-term confinement is sufficient to drive monocyte-to-macrophage differentiation through a mechanoepigenetic pathway. In vivo, differentiating monocytes exhibited flattened nuclei in the liver capsule, indicative of confinement by surrounding stromal and parenchymal structures. Using a custom cell confiner to recapitulate this confined niche, we found that confinement induces macrophage-like protrusive architectures, enhances motility, and upregulates macrophage-associated genes in RAW264.7 and THP-1 monocyte-lineage cells. Notably, extending this paradigm to primary murine bone-marrow, human umbilical-cord, and tissue-derived hepatic-associated monocytes yielded similar outcomes, thus enhancing phagocytic capacity, directly demonstrating that mechanical confinement can program monocytes into macrophages. Mechanistically, we found that confinement activates KDM6B, leading to H3K27me3 demethylation, which derepresses macrophage-specific transcriptional programs. Pharmacological inhibition of KDM6B with GSK-J4 restored H3K27me3 and blocked macrophage differentiation both in vitro and in vivo. These findings define a KDM6B-H3K27me3 axis that links nuclear mechanics to transcriptional reprogramming, positioning mechanical confinement as a "super-enhancer-like" cue for engineer macrophage function in therapeutic and bioengineering contexts.

cell biology↗

bioRxiv2024

Magnetoelectric Microrobots for Spinal Cord Injury Regeneration

Regenerative medicine continually seeks effective methods to address spinal cord injuries (SCI), which are known for their limited regenerative potential. Despite advances in neural progenitor cell (NPC) transplants for spinal cord injuries, challenges related to graft survival, reliable in vivo differentiation, and neural integration significantly hinder real functional recovery and limit clinical outcomes. This study introduces NPCbots, biohybrid microrobots engineered by integrating human-induced pluripotent stem cell-derived NPCs with magnetoelectric nanoparticles composed of cobalt ferrite-barium titanate. These enable magnetic navigation and neuronal stimulation, enhancing targeted therapeutic interventions. Our lab-on-a-chip system allows for the mass production of NPCbots, ensuring their differentiation and biocompatibility. Remarkably, in a zebrafish model of SCI, NPCbots stimulated by an alternating magnetic field demonstrated rapid in vivo differentiation and integration into damaged neural pathways, significantly enhancing neural regeneration. Within three days, injured zebrafish treated with NPCbots exhibited almost normal swimming behavior and significantly improved exploratory behavior, showcasing the potential of NPCbots to swiftly repair neural structures and restore the central nervous systems functionality in spinal cord injury models through non-invasive means. Additionally, precise in vitro and in vivo manipulation of NPCbots indicates their broader application in various neurodegenerative disorders, offering a promising route for effective spinal cord and neurological recovery.

neuroscience↗

bioRxiv2023

Vaccinia virus induces EMT-like transformation and RhoA-mediated mesenchymal migration

The emerging outbreak of monkeypox is closely associated with the viral infection and spreading, threatening global public health. Virus-induced cell migration facilitates viral transmission. However, high-resolution dynamics and mechanisms underlying this type of cell migration remain unclear. Here, we investigate the motility of cells infected by vaccinia virus (VACV), a close relative of monkeypox, through combining multi-omics analyses and high-resolution live-cell imaging. We find that, upon VACV infection, the epithelial cells undergo EMT-like transformation, during which they lose intercellular junctions and acquire the migratory capacity to promote viral spreading. After transformation, VACV-induced mesenchymal migration is highly dependent on the actin cytoskeleton and RhoA signaling, which is responsible for the depolymerization of robust actin stress fibers, the leading-edge protrusion formation, and the rear-edge recontraction. Our study reveals how poxviruses alter the epithelial phenotype and regulate RhoA signaling to induce fast migration, providing a unique perspective to understand the pathogenesis of poxviruses.

cell biology↗

bioRxiv2022

LCK-14-3-3ζ-TRPM8 axis for regulating TRPM8 function/assembly promotes pancreatic cancer malignancy

The transient receptor potential melastatin 8 (TRPM8), function as a Ca2+-permeable channel in the plasma membrane (PM). Dysfunction of TRPM8 is associated with human pancreatic cancer and several other diseases in clinical patients, but with unclear underlying mechanisms. Here, we found lymphocyte-specific protein tyrosine kinase (LCK) directly interacts with TRPM8 and potentiates TRPM8 phosphorylation at Y1022. LCK positively regulated channel function characterized by increased TRPM8 currents densities through enhancing TRPM8 multimerization. Furthermore, 14-3-3{zeta} interacted with TRPM8 and positively modulated channel multimerization. LCK significantly enhanced the binding of 14-3-3{zeta} and TRPM8, whereas mutant TRPM8-Y1022F impaired TRPM8 multimerization and the binding of TRPM8 and 14-3-3{zeta}. Knockdown of 14-3-3{zeta} impaired the regulation of LCK on TRPM8 multimerization. Additionally, TRPM8 phosphotyrosine at Y1022 feedback regulated LCK activity by inhibition of Tyr505 phosphorylation and modulation of LCK ubiquitination. Finally, we revealed the importance of TRPM8 phosphorylation at Y1022 in the proliferation, migration and tumorigenesis of pancreatic cancer cells. Our findings demonstrate that LCK-14-3-3{zeta}-TRPM8 axis for regulating TRPM8 assembly, channel function, LCK activity and providing potential therapeutic targets for pancreatic cancer.

cell biology↗

bioRxiv2021

TACAN is a novel regulator of PKD2

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in membrane receptor PKD1 or cation channel PKD2. TACAN (also named TMEM120A), recently reported as an ion channel in neuron cells for mechano and pain sensing, is also distributed in diverse non-neuronal tissues such as kidney, heart and intestine, suggesting its involvement in other functions. In this study, we found that TACAN is in complex with PKD2 in native renal cell lines. Using the two-electrode voltage clamp in Xenopus oocytes we found that TACAN inhibited the channel activity of PKD2 gain-of-function mutant F604P. The first and last transmembrane domains of TACAN were found to interact with the PKD2 C-and N-terminal portions, respectively. We showed that the TACAN N-terminus acted as a blocking peptide and that TACAN inhibits the PKD2 function through the PKD2/TACAN binding. By patch clamping in mammalian cells, we found that TACAN inhibits both the single channel conductance and open probability of PKD2 and mutant F604P. PKD2 co-expressed with TACAN, but not PKD2 alone, exhibited pressure sensitivity. Furthermore, we also found that TACAN aggravates PKD2-dependent tail curvature and pronephric cysts in larval zebrafish, in support of the in vitro inhibitory effects of TACAN. In summary, this study revealed that TACAN acts as a PKD2 inhibitor and mediates mechano sensitivity of the PKD2/TACAN channel complex.

physiology↗