Biology subjects

Pi, S.

Publications and source records attributed to Pi, S..

4 recordsLinked to original sources

bioRxiv2025

Electroporation-Based Gene Delivery and Whole-Organoid Imaging in Human Retinal Organoids

Human retinal organoids (hRetOrg) derived from human induced pluripotent stem cells (hiPSCs) have emerged as powerful in vitro systems for studying retinal development, modeling retinal diseases, and evaluating therapeutic strategies. However, current genetic manipulation approaches, such as stable hiPSC line generation and viral transduction, are laborious, costly, and inefficient, with limited spatial specificity and high variability. Here, we report a rapid, scalable, and spatially precise electroporation-based platform for efficient plasmid-based gene delivery in early-stage hRetOrg. This method enables tunable and region-specific transfection of retinal progenitor cells without viral vectors or clonal selection. Coupled with resonant-scanning two-photon microscopy, this approach allows fast live cell imaging of whole organoids with subcellular resolution. This versatile system supports high-throughput genetic manipulation and imaging in intact hRetOrg, advancing studies of human retinal development, gene function, and disease. MotivationhRetOrgs offer an unprecedented platform for functional genetic studies of human retinal development and disease. However, existing methods for gene manipulation in hRetOrg are limited by low throughput, inefficiency, and lack of scalability, hindering systematic analysis of gene function and regulatory elements. To address these limitations, we developed a streamlined, high-efficiency pipeline that enables spatially targeted electroporation of hRetOrg during early retinogenesis, combined with fast, high-resolution imaging of whole organoids using two-photon microscopy, allowing studies at both tissue and subcellular scales.

developmental biology↗

bioRxiv2024

Nuclear speckle rejuvenation alleviates proteinopathies at the expense of YAP1

Current treatments targeting individual protein quality control pathways have limited efficacy in alleviating proteinopathies, highlighting the prerequisite for a common druggable target capable of global proteostasis modulation. Building upon our prior research establishing nuclear speckles as pivotal membrane-less organelles for transcriptional control of proteostasis, we aim to alleviate proteinopathies through nuclear speckle rehabilitation. We identified pyrvinium pamoate as a nuclear speckle rehabilitator that enhances protein quality control gene expression and suppresses YAP1 transcriptional activity via decreasing the surface/interfacial tension of nuclear speckle condensates through interaction with the intrinsically disordered region of nuclear speckle scaffold protein SON. In pre-clinical models, nanomolar pyrvinium pamoate protected against retinal degeneration and tauopathy mainly by promoting autophagy and ubiquitin-proteasome activity in a SON-dependent manner without causing stress. Aberrant nuclear speckle morphology, reduced protein quality control and increased YAP1 activity were observed in human tauopathies. Our study provides proof-of-principle of targeting nuclear speckles to ameliorate proteinopathies.

cell biology↗

bioRxiv2023

Volumetrically tracking retinal and choroidal structural changes in central serous chorioretinopathy

Central serous chorioretinopathy (CSCR) leads to accumulation of subretinal fluid and retinal thickness change, which can be readily detected in clinics using optical coherence tomography (OCT). However, current quantification methods usually require sophisticated processing such as retinal layer segmentations, and volumetric visualization of structural changes is generally challenging, which can hinder fast and accurate assessment of disease progression and/or treatment efficacy. In this study, we developed an algorithm that can register the OCT scans acquired from different visits without requiring prior layer segmentation and calculated the three-dimensional (3-D) structural change maps for patients with CSCR. Our results demonstrate that this tool can be useful in monitoring the progression of CSCR and revealing the resolution of pathologies following treatment automatically with minimal pre-processing.

bioengineering↗

bioRxiv2023

Scalable Solar-Driven Chemical Production by Semiconductor Biohybrids Synthesized from Wastewater Pollutants

Semiconductors biohybrids integrate the best of biological catalysts and semiconductor nanomaterials for solar-to-chemical conversion. To realize the potential of hybrid systems at the commercial level, it remains an urgent need for cost-competitive and environmentally friendly approaches to scaling up. Here, we successfully tackle this challenge through developing biohybrid route that co-utilize multi-pollutants in wastewater to produce semiconductor biohybrids in-situ for solar-to-chemical production. To achieve cost-effective biohybrid production, we introduced an aerobic sulfate reduction pathway into Vibrio natriegens to enable the direct utilization of the heavy metal ions (i.e., Cd2+), sulfate, and organics in the wastewater to biosynthesize functional semiconductor nanoparticles in living V. natriegens. Furthermore, 2,3-butanediol biosynthetic pathway was introduced into the V. natriegens hybrid to couple the solar energy for enhanced bioproduction. We demonstrated the scalability of this system in a 5-L illuminated fermenter using wastewater as the feedstock, which resulted in production of 13 g/L of 2,3-butanediol. Life cycle analysis showed this specific biohybrid route had a significantly lower cost and reduced CO2 emission compared to both pure sugars fermentation and fossil-based routes. In addition to providing a promising step toward sustainable commercializing semiconductor biohybrids for biomanufacturing, our work may lead to hybrid living matter toward future waste to wealth conversion.

synthetic biology↗