Biology subjects

Na, C.-H.

Publications and source records attributed to Na, C.-H..

4 recordsLinked to original sources

bioRxiv2026

Human endogenous retrovirus envelope proteins alter extracellular vesicle cellular interactions and biodistribution

Extracellular vesicles (EVs) are versatile therapeutic candidates due to biological roles in intercellular communication and amenability to bioengineering. Compared with lipid nanoparticles (LNPs), native or surface-modified EVs may have favorable immunogenicity and biodistribution profiles. However, when administered intravenously (IV), EVs are rapidly cleared and accumulate mostly in the liver and spleen. With the goal of modifying EV biodistribution, we engineered EVs to display the human endogenous retrovirus (HERV) envelope glycoprotein Syncytin-1, an SLC1A5-binding fusogenic viral protein essential for syncytiotrophoblast formation in pregnancy. Here, we comprehensively characterize engineered Syncytin-1+ EVs, examine their interactions with cells in vitro, and assay biodistribution, immunogenicity, and pharmacokinetics ex vivo and in vivo in non-human primates. IV-administered Syncytin-1+ EVs are well tolerated, persist in the blood stream, and have altered organ biodistribution compared with unmodified EVs, suggesting therapeutic potential of Syncytin-1+ EVs at specific sites.

bioengineering↗

bioRxiv2026

NON-REDUNDANT ROLES OF COPPER TRANSPORTERS ATP7A AND ATP7B IN NORADRENERGIC SIGNALING

Menkes disease and Wilson disease are debilitating neurometabolic disorders caused by mutations in the copper (Cu) transporters ATP7A and ATP7B, respectively. In either disease, normalization of systemic Cu levels often does not eliminate neurological deficits, suggesting dysregulated Cu homeostasis within vulnerable neuronal populations. However, the specific roles of ATP7A and ATP7B and the extent of their functional redundancy in neurons remain poorly defined. Here, we selectively deleted Atp7a or Atp7b in noradrenergic neurons, which express both transporters and require Cu for catecholamine biosynthesis. ATP7A deletion reduced Cu levels in the locus coeruleus, disrupted dopamine-{beta}-hydroxylase localization, impaired norepinephrine synthesis, and induced proteomic signatures of defective vesicular trafficking and proteostasis, culminating in neurodegeneration and impaired regulation of energy balance and adaptive thermogenesis. In contrast, ATP7B deletion preserved Cu levels but altered intracellular Cu utilization, resulting in catecholamine imbalance, -synuclein upregulation, aberrant dopamine-{beta}-hydroxylase distribution, and dysregulated thermogenesis. These findings establish ATP7A and ATP7B as non-redundant regulators of noradrenergic function within neural circuits governing metabolic and energy homeostasis and provide a mechanistic framework for persistent neurological pathology independent of systemic Cu levels.

physiology↗

bioRxiv2025

Transcriptomic and protein analysis of human cortex reveals genes and pathways linked to NPTX2 disruption in Alzheimer's disease

BackgroundCognitive resilience to Alzheimers disease (AD) pathology is associated with preserved expression of NPTX2, an activity-regulated synaptic protein involved in circuit plasticity, excitation-inhibition balance, and complement-linked synapse regulation. However, the broader molecular programs coordinated with NPTX2 in resilient individuals remain unclear. MethodsWe analyzed postmortem middle temporal gyrus tissue using targeted PRM-MS proteomics in 135 individuals and bulk RNA-seq in an expanded 575-sample cohort. NPTX2-associated molecular coordination was assessed within cognitively normal low-pathology controls (CN-Lo), cognitively normal high-pathology controls (CN-Hi), mild cognitive impairment (MCI), and AD. Correlation-based approaches were applied using NPTX2 protein and NPTX2 mRNA expression as anchors to define resilience mechanisms in CN-Hi subjects. ResultsNPTX2 protein abundance was preserved across all controls regardless of age and pathology but reduced in MCI and AD. NPTX2 mRNA expression was also invariant across pathology within controls and reduced in MCI and AD but decreased markedly with age. Targeted proteomics identified NPTX2 relationships with synaptic and inhibitory-circuit proteins that were preserved across control groups, alongside CN-Hi-specific recruitment of trafficking, lysosomal, metabolic, and proteostasis-associated proteins. Transcriptome-wide correlations with NPTX2 revealed differences in gene co-expression between groups, identifying a prominent activity-dependent program including BDNF, VGF, SCG2, SST, SERTM1, DUSP4, and EGR4, that was preserved in both CN-Lo and CN-Hi subjects, while genes recruited to the NPTX2 network specifically in CN-Hi implicated immune, neuroprotective, translation, and proteostasis-related pathways. Coupling differential gene expression analysis with co-expression, we further identified five candidate resilience genes whose expression and NPTX correlation was preserved across controls, but lost in MCI and AD: SST, MAL2, TAC1, SERTM1, and RFK. Expression of genes in distinct NPTX2 co-expression classes can be freely explored in our bulk RNA-seq data and other public AD transcriptomic datasets at NeMO Analytics. ConclusionFindings suggest that cognitive resilience in the context of AD neuropathology engages a coordinated molecular state distinct from both persevered cognition without pathology and MCI/AD, which is organized around preserved and selectively remodeled NPTX2-associations. Rather than reflecting broad transcript abundance changes, resilience was characterized by maintained synaptic and inhibitory programs, and adaptive proteostasis and trafficking pathways that distinguish resilient high-pathology individuals from low-pathology controls or symptomatic AD.

bioinformatics↗

bioRxiv2023

Biomarker discovery in progressive supranuclear palsy from human cerebrospinal fluid using mass spectrometry-based proteomics

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder that is often misdiagnosed as Parkinsons Disease (PD) because of shared symptoms. PSP is characterized by the accumulation of tau protein in specific brain regions, which results in loss of balance, gaze impairment, and dementia. Diagnosing PSP is often challenging, and theres a significant demand for reliable biomarkers. However, existing biomarkers, including tau protein and neurofilament light chain (NfL) levels in cerebrospinal fluid (CSF), show inconsistencies in distinguishing PSP from other neurodegenerative disorders. To overcome these limitations, we conducted a comprehensive proteome analysis for CSF samples from 40 PSP, 40 PD, and healthy controls (HC) using the tandem mass tag-based quantification method, identifying 3,653 unique proteins. Our statistical analysis identified 190, 152, and 247 differentially expressed proteins when comparing PSP vs. HC, PSP vs. PD, and PSP against both PD and HC, respectively. Gene set enrichment analysis and interactome analysis conducted with the differentially expressed proteins in PSP CSF indicated that most of them were implicated in cell adhesion, cholesterol metabolism, and glycan biosynthesis. Cell-type enrichment analysis revealed that neuronally-derived proteins were predominant among the differentially expressed proteins. Potential biomarker classification performance showed that ATP6AP2 (reduced in PSP) had the highest AUC (0.922), followed by NEFM, EFEMP2, LAMP2, CHST12, FAT2, B4GALT1, LCAT, CBLN3, FSTL5, ATP6AP1, and GGH. This is the first large-scale mass spectrometry-based proteome analysis to discover CSF PSP biomarkers differentiating from both controls and PD, thereby laying a foundation for further development and validation.

systems biology↗