Biology subjects

Zheng, J. J.

Publications and source records attributed to Zheng, J. J..

8 recordsLinked to original sources

bioRxiv2026

An Integrated Multi-omics Single Cell Atlas of the Human RPE and Choroid

The retinal pigment epithelium and choroid are critical for supporting the function and maintaining the homeostasis of the outer retina, and their dysfunction underlies a range of inherited and complex ocular diseases. To comprehensively characterize the cellular, transcriptomic, and epigenomic heterogeneity and dynamics within these tissues, we assembled an integrated multi-omics reference atlas comprising 719,813 single-cell/single-nucleus transcriptomes and 234,007 snATAC-seq profiles from 102 ancestrally diverse donors spanning 0 to 99 years of age, including cells from both the macula and periphery. This atlas resolves 48 distinct cell types or states and catalogs 448,567 open chromatin regions. Specifically, we resolved five distinct RPE subpopulations organized along a central-to-peripheral spatial axis, alongside two distinct stress/senescence states. We reconstructed the transcriptomic and epigenetic zonation of endothelial cells and expanded choroidal stromal heterogeneity by characterizing 11 fibroblast and two pericyte types. Age-associated compositional analysis revealed a significant fractional depletion of melanocytes, PI16+ fibroblasts, and venule endothelial cells with age, alongside a modest relative loss of central RPE and a corresponding increase in far-peripheral RPE. Cell-type-specific aging transcriptomics uncovered shared pathways related to inflammatory responses alongside distinct cell-type-specific signatures. Notably, significant age-associated epigenetic changes concentrated in the macula during the transition from early-to-middle adulthood and remained stable into old age, with transcription factors from the AP-1/bZIP family emerging as the dominant enriched motifs. Finally, integrating this atlas with AMD GWAS data provides novel variant-to-gene evidence implicating LIPG and COL4A3 in AMD pathogenesis. Together, this multi-omics atlas serves as both an invaluable community reference and a powerful discovery engine that translates genetic risk signals into localized target cells and candidate mechanisms, laying a foundation for understanding RPE/choroid biology in health and disease.

genomics↗

bioRxiv2026

An Integrated muti-omics cell atlas of the human trabecular meshwork and ciliary body

The trabecular meshwork (TM) and ciliary body (CB) regulate aqueous humor dynamics and intraocular pressure (IOP), and TM/Schlemms canal (SC) dysfunction underlies glaucoma. Here, we present a spatially resolved multi-omics atlas of human TM and CB, integrating snRNA-seq, scRNA-seq, and snATAC-seq from over one million cells and nuclei across 112 donors with Xenium spatial transcriptomics. We identified 9 major cell classes and 21 cell types, revealing heterogeneity, including undercharacterized fibroblast and epithelial subpopulations. Spatial mapping supported TM fibroblast zonation and CB epithelial organization. Regulatory analyses identified cell type-specific programs, including OTX/PAX networks in CB epithelium and SMAD3/TGF-{beta} signaling in fibroblasts. Integration with glaucoma loci showed enrichment of non-coding variants in regulatory elements associated with POAG and PACG. Age- and ancestry-associated remodeling revealed divergent fibroblast aging with increased PIEZO1, suggesting impaired outflow and elevated IOP. Together, this high-resolution atlas links cellular, regulatory, and genetic variation to anterior segment function and glaucoma susceptibility.

genomics↗

bioRxiv2025

Simultaneous Isolation and Characterization of Lipoprotein Classes in Plasma, Including HDL Subclasses and the Uncharacterized Dense HDL

Lipoproteins (LPP) and extracellular vesicles are carriers of extracellular small RNA, with potential applications both in the areas of diagnostics and therapeutics. Lipid nanoparticles overlap across a range of densities and sizes in plasma, making them difficult to isolate intact and without contamination from other plasma components. Accurate characterization of their cargo through efficient isolation from other plasma components is required to understand their function. Here we describe the simultaneous separation of LPP classes using sequential flotation ultracentrifugation followed by size exclusion chromatography from 500{micro}L of starting plasma. Using western blot, denaturing and non-denaturing gel electrophoresis, nuclear magnetic resonance, and electron microscopy, we demonstrate separation of the LPP classes with minimal contamination. We also show unique lipidomic, proteomic and small RNA signatures for each LPP class, including, for the first time, very high density high density lipoprotein particles in the density range of 1.21-1.25 g/mL. MotivationIn plasma, lipid nanoparticles overlap in size and density, making it difficult to separate and isolate intact particles. Additionally, currently available methods do not allow for simultaneous characterization and isolation of these particles. This method resolves both challenges. The results presented also analyze and describe the presence of known lipoprotein particles, as well as those that have been previously under-characterized.

molecular biology↗

bioRxiv2025

Trifluoroacetate reduces plasma lipid levels and the development of atherosclerosis in mice

Trifluoroacetate (TFA) has been assumed to be an innocuous counterion (to cationic amino acid side chains) present in countless synthetic bioactive peptides and a few FDA-approved therapeutics. We show here that TFA is in fact bioactive and causes dramatic biological effects in multiple strains of mice and cultured human and rat liver cells. In high-fat diet (HFD)-fed low-density lipoprotein receptor-null (LDLr-/-) mice, TFA reduces the levels of plasma cholesterol, triglycerides, and the development of atherosclerotic lesions following either oral or intraperitoneal administration. These physiological effects were observed with TFA alone, or with TFA present as a counterion of a variety of short, unrelated synthetic peptide sequences. Mechanistic investigations including RNA-seq, confocal microscopy, western blotting, metabolomics, proteomics, pharmacokinetics, and biochemical assays indicated that TFA induces peroxisome proliferation by activating peroxisome proliferator-activated receptor (PPAR)-alpha. We confirmed that TFA also caused peroxisome proliferation and downstream phenotypic effects in cultured human and rat liver cells, wild-type C57/Bl mice, and apolipoprotein E-null (apoE-/-) mice, leading to anti-atherosclerotic effects in the latter strain. Given that TFA is a counterion in many peptides employed in early research and development settings, these findings raise the possibility that TFA may be confounding or contributing to phenotypic changes observed in many studies involving peptides. Although our studies suggest that TFA or its analogues might have therapeutic applications, it should be noted that TFA is also a persistent environmental contaminant that is found at high levels in humans relative to other polyfluoroalkyl substances (PFAS), and is a major metabolite following treatment of patients with common inhaled anesthetics, suggesting that the biological effects reported here could have other implications for human health.

biochemistry↗

bioRxiv2024

MIP3α-RelMtb intranasal DNA vaccination induces reactive T-cell infiltration into the lungs in mice and macaques

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the leading cause of mortality due to a single infectious organism. While generally curable, TB requires a lengthy and complex antibiotic regimen, due in large part to bacteria that can shift to a persistent state in the presence of antibiotic pressure. RelMtb is the primary enzyme regulating the stringent response, which contributes to the metabolic shift of Mtb to a persistent state. Targeting RelMtb with a vaccine to eliminate persistent bacteria through the induction of RelMtb-specific T-cell immunity in combination with antibiotics to kill dividing bacteria has shown promise in model systems. In a mouse model of Mtb infection, a vaccine created by genetically fusing relMtb to the chemokine macrophage inflammatory protein 3 (MIP3), a ligand for the CC chemokine receptor type 6 (CCR6) present on immature dendritic cells, has been shown to enhance T-cell responses and accelerate eradication of infection in mouse models compared to a vaccine lacking the chemokine component. In this study, immunogenicity studies in the mouse and rhesus macaque models provide evidence that intranasal administrations of the DNA form of the MipRel vaccine led to enhanced lung infiltration of T cells after a series of immunizations. Furthermore, despite similar T-cell immunity seen in PBMCs between MipRel and Rel vaccinations, lung and bronchoalveolar lavage cell samples are more enriched for cytokine-secreting T cells in MipRel groups compared to Rel groups. We conclude that intranasal immunization with a MIP-3 fusion vaccine represents a novel strategy for use of a simple DNA vaccine formulation to elicit T-cell immune responses within the respiratory tract. That this formulation is immunogenic in a non-human primate model historically viewed as poorly responsive to DNA vaccines indicates the potential for clinical application in the treatment of Mtb infection, with possible application to other respiratory pathogens. Future studies will further characterize the protective effect of this vaccination platform.

immunology↗

bioRxiv2023

Chromosomal Duplications of MurZ (MurA2) or MurA (MurA1), Amino Acid Substitutions in MurZ (MurA2), and Absence of KhpAB Obviate the Requirement for Protein Phosphorylation in Streptococcus pneumoniae D39

GpsB links peptidoglycan synthases to other proteins that determine the shape of the respiratory pathogen Streptococcus pneumoniae (pneumococcus; Spn) and other low-GC Gram-positive bacteria. GpsB is also required for phosphorylation of proteins by the essential StkP(Spn) Ser/Thr protein kinase. Here we report three classes of frequently arising chromosomal duplications ({approx}21-176 genes) containing murZ (MurZ-family homolog of MurA) or murA that suppress {Delta}gpsB or {Delta}stkP. These duplications arose from three different repeated sequences and demonstrate the facility of pneumococcus to modulate gene dosage of numerous genes. Overproduction of MurZ or MurA alone or overexpression of MurZ caused by {Delta}khpAB mutations suppressed {Delta}gpsB or {Delta}stkP phenotypes to varying extents. {Delta}gpsB and {Delta}stkP were also suppressed by MurZ amino-acid changes distant from the active site, including one in commonly studied laboratory strains, and by truncation or deletion of the homolog of IreB(ReoM). Unlike in other Gram-positive bacteria, MurZ is predominant to MurA in pneumococcal cells. However, {Delta}gpsB and {Delta}stkP were not suppressed by {Delta}clpCP, which did not alter MurZ or MurA amounts. These results support a model in which regulation of MurZ and MurA activity, likely by IreB(Spn), is the only essential requirement for protein phosphorylation in exponentially growing D39 pneumococcal cells.

microbiology↗

bioRxiv2020

S1-Domain RNA-Binding Protein (CvfD) Is a New Post-Transcriptional Regulator That Mediates Cold Sensitivity, Phosphate Transport, and Virulence in Streptococcus pneumoniae D39

Post-transcriptional gene regulation often involves RNA-binding proteins that modulate mRNA translation and/or stability either directly through protein-RNA interactions or indirectly by facilitating the annealing of small regulatory RNAs (sRNAs). The human pathogen Streptococcus pneumoniae D39 (pneumococcus) does not encode homologs to RNA-binding proteins known to be involved in promoting sRNA stability and function, such as Hfq or ProQ, even though it contains genes for at least 112 sRNAs. However, the pneumococcal genome contains genes for other RNA-binding proteins, including at least six S1-domain proteins; ribosomal protein S1 (rpsA), polynucleotide phosphorylase (pnpA), RNase R (rnr), and three proteins of unknown functions. Here, we characterize the function of one of these conserved, yet uncharacterized S1-domain proteins, SPD_1366, which we have renamed CvfD (Conserved virulence factor D), since loss of this protein results in an attenuation of virulence in a murine pneumonia model. We report that deletion of cvfD impacts expression of 144 transcripts including the pst1 operon, encoding the phosphate transport system 1 in S. pneumoniae. We further show that CvfD post-transcriptionally regulates the PhoU2 master regulator of the pneumococcal dual phosphate transport system by binding phoU2 mRNA and impacting PhoU2 translation. CvfD not only controls expression of phosphate transporter genes, but also functions as a pleiotropic regulator that impacts cold sensitivity and the expression of sRNAs and genes involved in diverse cellular functions, including manganese uptake and zinc efflux. Together, our data show that CvfD exerts a broad impact on pneumococcal physiology and virulence, partly by post-transcriptional gene regulation. SIGNIFICANCERecent advances have led to the identification of numerous sRNAs in the major human respiratory pathogen, S. pneumoniae. However, little is known about the functions of most sRNAs or RNA-binding proteins involved in RNA biology in pneumococcus. In this paper, we characterize the phenotypes and one target of the S1-domain RNA-binding protein CvfD, a homolog of "general-stress protein 13" identified, but not extensively characterized in other Firmicute species. Pneumococcal CvfD is a broadly pleiotropic regulator, whose absence results in misregulation of divalent cation homeostasis, reduced translation of the PhoU2 master regulator of phosphate uptake, altered metabolism and sRNA amounts, cold sensitivity, and attenuation of virulence. These findings underscore the critical roles of RNA biology in pneumococcal physiology and virulence.

microbiology↗

bioRxiv2020

Selective Plane Illumination Microscopy and Computing Reveal Differential Obliteration of Retinal Vascular Plexuses

Murine models of visual impairment provide micro-vascular insights into the 3-D network disarray in retinopathy. Current imaging and analysis tend to be confined to the 2-D retinal vasculature. We hereby integrated selective plane illumination imaging or known as light-sheet fluorescence microscopy (LSFM) with dual-illumination, followed by computational analyses, to reveal the topological network of vertical sprouts bridging the primary and secondary plexuses in a postnatal mouse model of oxygen-induced retinopathy (OIR). We revealed a preferential obliteration of the secondary plexus and bridging vessels despite a relatively unscathed primary plexus. We compared the local versus global vascular connectivity using clustering coefficients and Euler numbers, respectively. The global vascular connectivity in hyperoxia-exposed retinas was significantly reduced (p < 0.05, n = 5 vs. normoxia), whereas the local connectivity was preserved (p > 0.05, n = 5 vs. normoxia). We further applied principal component analysis (PCA) to automatically segment the vertical sprouts, corroborating the preferential obliteration of the interconnection between vertical sprouts and secondary plexuses that were accompanied with impaired vascular branching and connectivity, and reduced vessel volumes and lengths (p < 0.05, n=5 vs. normoxia). Thus, integration of 3-D selective plane illumination with computational analyses allows for early detection of global and spatially-specific vaso-obliteration, but preserved local reticular structure in response to hyperoxia-induced retinopathy.

bioengineering↗