Biology subjects

Lo, C. H.

Publications and source records attributed to Lo, C. H..

10 recordsLinked to original sources

bioRxiv2026

Comparative Proteomics Reveals Cell-Type-Specific Heterogeneity of Human Neural Cell-Derived Extracellular Vesicles

Extracellular vesicles (EVs) are increasingly explored as biomarkers and as drug delivery vehicles for the brain, yet how EV cargo differs among neural cell types at baseline remains poorly defined. This gap limits both the interpretation of disease-associated EV changes and the rational choice of EV source for therapeutic use. Here, we compared EVs from human neuronal-like SH-SY5Y cells (N-EV), astrocytes (AS-EV), and HMC3 microglia (MG-EV) side by side using tandem mass tag (TMT)-based quantitative proteomics, with all samples analyzed in a single multiplexed batch. EV identity was supported by TEM, nanoparticle tracking analysis, and canonical MISEV2023 markers. Size, zeta potential, and protein content per vesicle were comparable across EV types, whereas N-EV showed the highest particle concentration and protein yield. Enrichment analyses and consensus clustering showed cargo consistent with parental-cell functions: neuronal connectivity and structural remodeling in N-EV, extracellular support and cellular interaction in AS-EV, and immune surveillance in MG-EV. Cross-comparison also revealed patterns beyond these canonical roles, including complement-associated cargo shared by N-EV and MG-EV and a Glial-EV signature of chromatin-associated and epigenetic regulatory proteins shared by AS-EV and MG-EV. We further defined cell-type-specific signature proteins; interaction networks of the larger sets were consistent with the enrichment results. Overall, these data provide a baseline comparative reference of EV proteomes from human neural cell models for interpreting disease-associated alterations, selecting EV sources for therapeutic use, and generating hypotheses on selective cargo sorting.

neuroscience↗

bioRxiv2026

Peptide allosteric inhibitor of TNFR1 signaling attenuates inflammation and rheumatoid arthritis pathology in human TNF transgenic mice

Inhibition of tumor necrosis factor receptor 1 (TNFR1) represents a major therapeutic strategy for chronic autoimmune and inflammatory diseases such as rheumatoid arthritis (RA). As current anti-TNF therapies can cause adverse side effects due to global blockade of the ligand, receptor-specific inhibition of TNFR1 signaling has emerged as a highly sought-after strategy. We have recently identified a novel peptide-based allosteric inhibitor, FKC (FKCRRWQWRMKK), that targets TNFR1 conformationally active region to alter receptor conformational states and disable receptor-ligand signaling complex. Here, we evaluated the therapeutic efficacy of FKC in a human TNF (hTNF) transgenic mouse model of RA. FKC treatment improves clinical RA scores in hTNF mice, accompanied by enhanced grip strength and increased walking distance. Importantly, FKC treatment inhibits TNF/TNFR1-mediated inflammation and attenuates RA pathology in hTNF mice. Together, our findings establish FKC as a promising new class of peptide-based therapeutics for chronic inflammatory diseases through selective inhibition of TNFR1 signaling.

immunology↗

bioRxiv2025

Aeon: an open-source platform to study the neural basis of ethological behaviours over naturalistic timescales

Ethological behaviours are a powerful tool for neuroscience since they leverage the robust neural computations shaped by the species evolution to study the neural basis of cognitive functions. However, such behaviours are often transitory and dependent on factors that vary over space, time and number of individuals, making them difficult to capture with standard laboratory tasks. Here we present Aeon, an open-source platform designed for continuous, long-term study of self-guided behaviours in multiple mice and simultaneous recording of brain activity within large, customizable habitats. By integrating specialized modules for navigation, nesting and sleeping, escaping, foraging, and social interaction, Aeon enables the expression of key ethological behaviours while achieving experimental control and multi-dimensional quantifications from sub-millisecond to month-long durations. Its software architecture ensures robust data acquisition via many synchronized data streams and delivers a new standardised, unified data format that yields seamless, integrated analysis pipelines. Using assays such as digging-to-threshold and social foraging, Aeon reveals how mice adapt strategies in a changing environment and in response to conspecifics. Aeon bridges ecological relevance with rigorous experimental control to advance our understanding of how neural circuit activity gives rise to a range of highly conserved and adaptive behaviours.

neuroscience↗

bioRxiv2024

Lysosome-acidifying nanoparticles rescue A30P α-synuclein induced neuronal death in cellular and Drosophila models of Parkinson's disease

Parkinsons disease (PD) is an age-related neurodegenerative disease characterized by histopathological hallmarks of Lewy bodies formed by accumulation of -synuclein (Syn) and progressive loss of dopaminergic neurons in the substantia nigra pars compacta of the midbrain, with clinical symptoms of motor deficits. Toxic protein accumulation of Syn in PD is associated with autolysosomal acidification dysfunction that contributes to defective autophagy-lysosomal degradation system. While lysosome-acidifying nanoparticles have been applied as therapeutics to ameliorate dopaminergic neurodegeneration in neurotoxin mediated or Syn aggregates induced mouse model of sporadic PD, lysosome-targeted approach has not yet been applied in synucleinopathy models of familial PD. Here, we report the first application of the new poly(ethylene tetrafluorosuccinate-co-succinate) (PEFSU)-based acidic nanoparticles (AcNPs) in A30P Syn overexpressing SH-SY5Y cells and Drosophila models of PD. In the cellular model, we showed that AcNPs restore lysosomal acidification, promote autophagic clearance of Syn, improve mitochondrial turnover and function, and rescue A30P Syn induced death in SH-SY5Y cells. In the Drosophila model, we demonstrated that AcNPs enhance clearance of Syn and rescue dopaminergic neuronal loss in fly brains and improve their locomotor activity. Our results highlight AcNPs as a new class of lysosome-acidifying therapeutic for treatment of PD and other proteinopathies in general.

neuroscience↗

bioRxiv2023

Defective lysosomal acidification contributes to TNFR1 mediated neuronal necroptosis in Alzheimer's disease

Background: Tumor necrosis factor (TNF) receptor 1 (TNFR1) signaling mediates neuronal necroptosis in Alzheimer's disease (AD). Interaction of TNFR1 signaling axis with autolysosomal pathway and the accumulation of necrosome molecules in impaired lysosomes have been shown to lead to necroptotic neuronal death. This has been attributed to the terminal failure of the autophagic process, primarily due to lysosomal degradation dysfunction. Being the final and determining step of the autolysosomal pathway, lysosomes with sufficient acidification as maintained by functional vacuolar (H+)-ATPase (V-ATPase) are required to achieve complete autophagic degradation of toxic cellular components. Here, we aim to investigate the role of defective lysosomal acidification in mediating TNFR1 induced neuronal necroptosis in AD. Methods: Neuropathological analysis of human post-mortem AD brains was performed to examine the correlation between TNFR1 induced neuronal necroptosis and autolysosomal dysfunction. Specifically, we probed for the level of V-ATPase subunits in AD brains to determine the extent of lysosomal acidification and function. Cell-based assays were conducted to understand the effect of TNFR1 activation in driving lysosomal acidification defect, proteolytic function, membrane integrity, autophagic impairment, mitochondrial dysfunction, and neuronal death in SH-SY5Y neuroblastoma cells. Furthermore, we applied lysosome-acidifying nanoparticles (AcNPs) to determine whether restoration of lysosomal acidification can rescue neuronal necroptosis in both TNF-treated SH-SY5Y cells and APPNL-G-F knock-in mouse model of AD. Results: We found that TNFR1 activated neuronal necroptosis correlated with autolysosomal dysfunction as characterized by downregulation of V-ATPase subunits and accumulation of autophagy receptor p62 in human AD brains. In cell culture, we showed for the first time that lysosomal acidification is only impaired in cells treated with TNF and not with other cytokines, contributing to inhibition of autophagic degradation in SH-SY5Y cells. TNF also disrupted lysosomal trafficking and membrane dynamics and induced lysosomal membrane permeabilization, followed by impaired autophagic clearance, defective mitochondrial turnover, reduced mitochondrial function, and neuronal death. Importantly, we demonstrated that AcNPs restored lysosomal, autophagic, and mitochondrial function, improved lysosomal membrane homeostasis, and rescued neuronal necroptosis in both TNF-treated SH-SY5Y cells and APPNL-G-F mice.

neuroscience↗

bioRxiv2023

Acidic nanoparticles restore lysosomal acidification and rescue metabolic dysfunction in pancreatic β-cells under lipotoxic condition

Type 2 diabetes (T2D), a prevalent metabolic disorder lacking effective treatments, is associated with lysosomal acidification dysfunction as well as autophagic and mitochondrial impairments. Here, we report a series of biodegradable poly(butylene tetrafluorosuccinate-co-succinate) (PBFSU) polyesters, comprising an 1,4-butanediol linker and varying ratios of tetrafluorosuccinic acid (TFSA) and succinic acid as components, to engineer new lysosome acidifying nanoparticles (NPs). Notably, TFSA NPs, which composed entirely of TFSA, exhibit the strongest degradation capability and superior acidifying property. We further reveal significant downregulation of lysosomal vacuolar (H+)-ATPase (V-ATPase) subunits, which are responsible for maintaining lysosomal acidification, in human T2D pancreatic islets and INS-1 {beta}-cells under lipotoxic condition. Treatment of TFSA NPs counteracts lipotoxicity in INS-1 {beta}-cells by restoring lysosomal acidification, autophagic function, and mitochondrial activity, along with promoting glucose-stimulated insulin secretion. Administration of TFSA NPs to high-fat diet T2D mice improves glucose clearance and reduces insulin resistance. These findings highlight the therapeutic potential of lysosome acidifying TFSA NPs for T2D. Graphical Table of Contents O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=168 SRC="FIGDIR/small/548395v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@faec9eorg.highwire.dtl.DTLVardef@1c4a6b5org.highwire.dtl.DTLVardef@19cd6ceorg.highwire.dtl.DTLVardef@1da9a4b_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

Integrated computational and in vivo models reveal Key Insights into Macrophage Be-havior during bone healing

Myeloid-derived monocyte and macrophages are key cells in the bone that contribute to remodeling and injury repair. However, their temporal polarization status and control of boneresorbing osteoclasts and bone-forming osteoblasts responses is largely unknown. In this study, we focused on two aspects of monocyte/macrophage dynamics and polarization states over time: 1) the injury-triggered pro- and anti-inflammatory monocytes/macrophages temporal profiles, 2) the contributions of pro-versus anti-inflammatory monocytes/macrophages in coordinating healing response. Bone healing is a complex multicellular dynamic process. While traditional in vitro and in vivo experimentation may capture the behavior of select populations with high resolution, they cannot simultaneously track the behavior of multiple populations. To address this, we have used an integrated a coupled ordinary differential equations (ODEs)-based framework describing multiple cellular species to in vivo bone injury data in order to identify and test various hypotheses regarding bone cell populations dynamics. Our approach allowed us to infer several biological insights including, but not limited to,: 1) anti-inflammatory macrophages are key for early osteoclast inhibition and pro-inflammatory macrophage suppression, 2) pro-inflammatory macrophages are involved in osteoclast bone resorptive activity, whereas osteoblasts promote osteoclast differentiation, 3) Pro-inflammatory monocytes/macrophages rise during two expansion waves, which can be explained by the anti-inflammatory macrophages-mediated inhibition phase between the two waves. In addition, we further tested the robustness of the mathematical model by comparing simulation results to an independent experimental dataset. Taken together, this novel comprehensive mathematical framework allowed us to identify biological mechanisms that best recapitulate bone injury data and that explain the coupled cellular population dynamics involved in the process. Furthermore, our hypothesis testing methodology could be used in other contexts to decipher mechanisms in complex multicellular processes. Author SummaryMyeloid-derived monocytes/macrophages are key cells for bone remodeling and injury repair. However, their temporal polarization status and control of bone-resorbing osteoclasts and boneforming osteoblasts responses is largely unknown. In this study, we focused on two aspects of monocyte/macrophage population dynamics: 1) the injury-triggered pro- and anti-inflammatory monocytes/macrophages temporal profiles, 2) the contributions of pro-versus anti-inflammatory monocytes/macrophages in coordinating healing response. In order to test various hypotheses regarding bone cell populations dynamics, we have integrated a coupled ordinary differential equations-based framework describing multiple cellular species to in vivo bone injury data. Our approach allowed us to infer several biological insights including: 1) anti-inflammatory macrophages are key for early osteoclast inhibition and pro-inflammatory macrophage suppression, 2) pro-inflammatory macrophages are involved in osteoclast bone resorptive activity, whereas osteoblasts promote osteoclast differentiation, 3) Pro-inflammatory monocytes/macrophages rise during two expansion waves, which can be explained by the anti-inflammatory macrophages-mediated inhibition phase between the two waves. Taken together, this mathematical framework allowed us to identify biological mechanisms that recapitulate bone injury data and that explain the coupled cellular population dynamics involved in the process.

immunology↗

bioRxiv2020

Computational modeling reveals a key role for polarized myeloid cells in controlling osteoclast activity during bone injury repair

Bone-forming osteoblasts and -resorbing osteoclasts control bone injury repair, and myeloid-derived cells such as monocytes and macrophages are known to influence their behavior. However, precisely how these multiple cell types coordinate and regulate each other over time to repair injured bone is difficult to dissect using biological approaches. Conversely, mathematical modeling lends itself well to this challenge. Therefore, we generated an ordinary differential equation (ODE) model powered by experimental data (osteoblast, osteoclast, bone volume, pro- and anti-inflammatory myeloid cells) obtained from intra-tibially injured mice. Initial ODE results using only osteoblast/osteoclast populations demonstrated that bone homeostasis could not be recovered after injury, but this issue was resolved upon integration of pro- and anti-inflammatory myeloid population dynamics. Surprisingly, the ODE revealed temporal disconnects between the peak of total bone mineralization/resorption, and osteoblast/osteoclast numbers. Specifically, the model indicated that osteoclast activity must vary greatly (>17-fold) to return the bone volume to baseline after injury and suggest that osteoblast/osteoclast number alone is insufficient to predict bone the trajectory of bone repair. Importantly, the values of osteoclast activity fall within those published previously. These data underscore the value of mathematical modeling approaches to understand and reveal new insights into complex biological processes.

physiology↗

bioRxiv2020

Potent inhibitors of toxic alpha-synuclein oligomers identified via cellular time-resolved FRET biosensor.

Preventing or reversing the pathological misfolding and self-association of alpha-synuclein (aSyn) can rescue a broad spectrum of pathological cellular insults that manifest in Parkinsons Disease (PD), Dementia with Lewy bodies (DLB), and other alpha-synucleinopathies. We have developed a high-throughput, FRET-based drug discovery platform that combines high-resolution protein structural detection in living cells with an array of functional and biophysical assays to identify novel lead compounds that protect SH-SY5Y cells from aSyn induced cytotoxicity as well as inhibiting seeded aSyn aggregation, even at nanomolar concentrations. Our combination of cellular and cell-free assays allow us to distinguish between direct aSyn binding or indirect mechanisms of action (MOA). We focus on targeting oligomers with the requisite sensitivity to detect subtle protein structural changes that may lead to effective therapeutic discoveries for PD, DLB, and other alpha-synucleinopathies. Pilot high-throughput screens (HTS) using our aSyn cellular FRET biosensors has led to the discovery of the first nanomolar-affinity small molecules that disrupt toxic aSyn oligomers in cells and inhibit cell death. Primary neuron assays of aSyn pathology (e.g. phosphorylation of mouse aSyn PFF) show rescue of pathology for two of our tested compounds. Subsequent seeded thioflavin-t (ThioT) aSyn aggregation assays demonstrate these compounds deter or block aSyn fibril assembly. Other hit compounds identified in our HTS are known to modulate oxidative stress, autophagy, and ER stress, providing validation that our biosensor is sensitive to indirect MOA as well.

neuroscience↗

bioRxiv2019

A novel small molecule screening platform for disrupting toxic tau oligomers in cells

Tauopathies, including Alzheimers disease, are a group of neurodegenerative disorders characterized by pathological aggregation of the microtubule binding protein tau. Recent studies suggest that toxic tau oligomers, which are soluble and distinct from insoluble beta-sheet fibrils, are central players in neuronal cell death. To exploit this new therapeutic window, we engineered two first-in-class FRET based biosensors that monitor tau conformations in cells. Because this new technology platform operates in cells, it enables high-throughput screening of small molecules that target tau oligomers while avoiding the uncertainties of idiosyncratic in vitro preparations of tau assemblies from purified protein. We found a small molecule, MK-886, that disrupts tau oligomers and reduces tau-induced cell cytotoxicity with nanomolar potency. Using SPR and an advanced single-molecule FRET technique, we show that MK-886 directly binds to tau and specifically perturbs the folding of tau monomer in the proline-rich and microtubule-binding regions. Furthermore, we show that MK-886 accelerates the tau aggregation lag phase using a thioflavin-T assay, implying that the compound stabilizes a non-toxic, on-pathway oligomer. The technology described here should generalize to the study and targeting of conformational ensembles within the aggregation pathways of most intrinsically disordered proteins.

neuroscience↗