Biology subjects

Ru, Q.

Publications and source records attributed to Ru, Q..

4 recordsLinked to original sources

bioRxiv2025

High-throughput 3D super-resolution imaging in deep tissue

Fluorescence images obtained with optical microscopes intrinsically suffer from blur and noise, which can be partially reversed by the deconvolution process. However, the deconvolution process is ill-conditioned, leading to a trade-off between detail preservation and noise suppression. Here, we develop 3D-FUDIP to fully decouple the deconvolution process into two parts: deblurring and denoising, achieving an 8-fold improvement in spatial resolution. By adopting the Poisson model, which obeys the quantum nature of photons, our 3D-FUDIP can be successfully applied to various noise conditions, especially low-light conditions where the photon number is generally extremely small. The results show that our 3D-FUDIP improves the SNR by up to 6-fold with only a one-fifth photon budget. Besides, 3D-FUDIP boosts the spatial bandwidth product (SBP) by one order of magnitude, allowing more spine details to be resolved within a larger imaging volume. By synergizing deep learning with these advances, we propose 3D-FUDIPn to further improve the imaging resolution. We demonstrate 3D-FUDIPs performance in various imaging systems, including confocal, two-photon, and light-sheet microscopes, showing compatibility and potential applications in biological science.

neuroscience↗

bioRxiv2024

GESIAP3.0: Sensor-based Image Analysis Program for Transmission Visualization In Vivo

Synaptic transmission mediated by various neurotransmitters influences a wide range of behaviors. However, understanding how neuromodulatory transmitters encode diverse behaviors and affect their functions remains challenging. Here, we introduce GESIAP3.0, an advanced, third-generation image analysis program based on genetically encoded sensors. This tool enables precise quantitative analysis of transmission in both awake, freely moving animals and immobilized subjects. GESIAP3.0 incorporates movement correction algorithms that effectively eliminate image displacement in behaving animals while optimizing synaptic information extraction and simplifying computations on commodity computers. Quantitative analysis of cholinergic, dopaminergic, and serotonergic transmission, corrected for tissue movement, revealed synaptic properties consistent with measurements from ex vivo wide-field and in vivo two-photon imaging under stable conditions. This validates the applicability of GESIAP3.0 for analyzing synaptic properties of neuromodulatory transmission in behaving animals.

bioengineering↗

bioRxiv2022

Cryo-EM structures reveal a dynamic transformation process of human alpha-2-macroglobulin working as a protease inhibitor

Human alpha-2-macroglobulin is a well-known proteases inhibitor against a broad spectrum of proteases. It also plays important roles in immunity, inflammation, and infections. Here, we report cryo-EM structures of human alpha-2-macroglobulin of the native state, the transformed state induced by its authentic substrate, human trypsin, and serial intermediate states between the native and the fully induced state. These structures exhibit distinct conformations, which reveal a dynamic transformation process of alpha-2-macroglobulin acting as a protease inhibitor. The results shed light on the molecular mechanism of alpha-2-macroglobulin entrapping substrates, and help to understand how alpha-2-macroglobulin possesses variant physiological functions.

biochemistry↗

bioRxiv2021

Tiam1-mediated synaptic plasticity drives comorbid depressive symptoms in chronic pain

Hyperactivity in the anterior cingulate cortex (ACC) drives comorbid depressive symptoms in chronic pain, but the cause of ACC hyperactivity is currently unclear. Ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, induces rapid and sustained antidepressant-like effects in chronic pain-induced depression in both patients and animal models. However, the mechanisms underlying ketamines sustained antidepressant effects remain elusive. Here, we show that Tiam1, a Rac1-specific guanine nucleotide exchange factor (GEF) that was previously identified as a critical mediator of NMDAR-dependent dendritic spine development, is activated in the ACC in chronic pain mice displaying depressive-like behaviors. Conditional deletion of Tiam1 from postnatal forebrain excitatory neurons, specific deletion of Tiam1 from ACC neurons, or pharmacological inhibition of the Tiam1-Rac1 signaling pathway prevents chronic pain-induced depressive-like behaviors in mice. Biochemical, morphological, and electrophysiological assays reveal that Tiam1 orchestrates synaptic structural and functional remodeling in ACC neurons via actin cytoskeleton reorganization and synaptic NMDAR stabilization. This Tiam1-coordinated synaptic plasticity underpins ACC hyperactivity and drives chronic pain-induced depressive-like behaviors. Ketamine induces sustained antidepressant effects in chronic pain by blocking Tiam1-mediated synaptic structural and functional plasticity in ACC neurons. Our results reveal Tiam1 as a key factor in the pathophysiology of chronic pain-induced depression and in the sustained antidepressant effects of ketamine in ACC neurons. These findings highlight Tiam1 as a potential therapeutic target for the treatment of comorbid depressive symptoms in chronic pain.

neuroscience↗