Biology subjects

Miao, S.

Publications and source records attributed to Miao, S..

7 recordsLinked to original sources

bioRxiv2026

Dual-mode ClfA-targeting DARPin biologics protect against diverse methicillin-resistant Staphylococcus aureus strains

Staphylococcus aureus uses the adhesin clumping factor A (ClfA) to bind fibrinogen and promote invasive infection through two distinct interfaces: an exposed, low-afinity site on the N3 head domain and a buried, high-afinity "dock, lock, and latch" (DLL) trench that is exposed only under shear. This dual-interface architecture allows limited antibody penetration, as antibodies typically block only the exposed site. Here, we establish a dual-mode inhibition strategy that overcomes this constraint by combining a high-afinity ClfA-binding designed ankyrin repeat protein (DARPin) with a fibrinogen {gamma}-chain peptide capable of occupying the DLL trench. Using cell-free click display and kinetics-guided afinity maturation, we engineer DARPin-{gamma}-peptide fusion biologics that simultaneously block both fibrinogen-binding interfaces. These molecules inhibit ClfA-fibrinogen interactions, prevent methicillin-resistant S. aureus agglutination in human plasma, neutralize major clinical ClfA variants, and confer Fc-independent protection in a lethal murine bacteremia model. This work provides a strategy for targeting antibody-intractable force-activated staphylococcal adhesins.

molecular biology↗

bioRxiv2025

Single-Cell eQTL Mapping Reveals Cell Type-Specific Genetic Regulation in Lung Cancer

Genome-wide association studies (GWAS) have identified over 50 lung cancer risk loci; however, the precise cellular context of these genetic mechanisms remains unclear due to limitations in bulk tissue eQTL analyses. Here, we present the largest single-cell eQTL atlas of human lung tissue to date, profiling 222 donors using multiplexed scRNA-seq. We identified 16,785 eQTLs across 17 cell types, with over 90% of sc-eQTLs and 59% eGene being cell-type-specific, and fewer than 23% were detectable in paired bulk datasets. Integration with GWAS for non-small cell lung cancer highlighted epithelial and immune cells as key contributors to genetic susceptibility, identifying 28 candidate genes within known risk loci and 24 in novel regions. Notably, 47% of established NSCLC susceptibility loci exhibited cell-type-specific pleiotropic genetic regulation. This study provides a valuable resource of lung sc-eQTLs and illuminates how genetic variation modulates gene expression in a cell-type-specific fashion, contributing to lung cancer susceptibility.

genetics↗

bioRxiv2022

FOXC2 marks and maintains the primitive spermatogonial stem cells subpopulation in the adult testis

In adult mammals, spermatogenesis embodies the complex developmental process from spermatogonial stem cells (SSCs) to spermatozoa. At the top of this developmental hierarchy lie a series of SSC subpopulations. Their individual identities as well as the relationships with each other, however, remain largely elusive. Using single-cell analysis and lineage tracing, we discovered both in mice and humans the quiescent adult SSC subpopulation marked specifically by forkhead box protein C2 (FOXC2). All spermatogenic progenies can be derived from FOXC2+ SSCs and the ablation of FOXC2+ SSCs led to the depletion of the undifferentiated spermatogonia pool. During germline regeneration, FOXC2+ SSCs were activated and able to completely restore the process. Germ cell specific Foxc2 knockout resulted in an accelerated exhaustion of SSCs and eventually led to male infertility. Furthermore, FOXC2 prompts the expressions of negative regulators of cell cycle thereby ensures the SSCs reside in quiescence. Thus, this work proposes that the quiescent FOXC2+ SSCs are essential for maintaining the homeostasis and regeneration of spermatogenesis in adult mammals.

developmental biology↗

bioRxiv2022

Fluorogenic U-rich internal loop (FLURIL) tagging with bPNA enables intracellular RNA and DNA tracking

We introduce herein a new strategy for intracellular RNA and DNA tracking that is robust, orthogonal and complementary to existing methods: Fluorogenic U-Rich Internal Loop (FLURIL) tagging with cell-permeable fluorophore-labeled bifacial Peptide Nucleic Acids (fbPNAs). Our approach uses an 8-nt (U4xU4) U-rich internal loop (URIL) in the RNA of interest (ROI) as a compact labeling site for fluorogenic triplex hybridization with a bPNA probe (~1 kD). FLURIL tagging thus replaces a 4 bp duplex stem with a labeled 4-base-triple hybrid stem of similar structure and mass. In contrast to existing strategies for RNA tracking, FLURIL tagging can be applied to internal, genetically encoded URIL RNA sites with minimal structural perturbation, co-expression of protein-fusion labels or significant increase in molecular weight and steric bulk. We demonstrate effective FLURIL tagging of intracellular (HEK-293) RNAs, ribonucleoprotein (RNP) complexes and live cell (U2-OS) tracking of genomic loci. FLURIL tracking was internally validated by direct comparison with the most widely used live-cell RNA labeling method, MS2-labeling with MCP-HaloTag and Janelia Fluor dyes. In addition, FLURIL-tagging correctly reported on the endogenous RNP in HEK293 cells formed from TAR DNA binding protein 43 (TDP-43-tdTomato) and UG repeat RNA. The FLURIL strategy was also successfully applied to guide RNA (gRNA) in CRISPR-dCas complexes to enable live cell tracking of a low-copy number genomic locus (IDR3), internally benchmarked against MS2/HaloTag labeling of CRISPR-Sirius gRNA targeted to a proximal locus (IDR2). Notably, FLURIL-tagged IDR2 exhibited similar brightness as loci targeted by CRISPR-Sirius gRNA complexes, which bear 8-MS2 hairpins for protein labeling. Together, these experiments show that FLURIL tagging can simply and reliably track intracellular RNA, RNPs, and DNA, with a streamlined molecular footprint relative to other methods. Importantly, these data also indicate that FLURIL tagging is fully compatible with existing labeling methods without crosstalk and may be used to broaden the scope of intracellular RNA and DNA tracking. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=195 SRC="FIGDIR/small/501035v1_figS1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1e6cc24org.highwire.dtl.DTLVardef@1646707org.highwire.dtl.DTLVardef@a80268org.highwire.dtl.DTLVardef@363193_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOScheme 1.C_FLOATNO FLURIL-tagging of RNAs with bPNA probes. (a) Triplex hybridization of a U-rich internal loop (URIL) with bPNA (blue) via base triple formation between the melamine base (M) and two uracil bases (inset). (b) General schematic of labeling strategy described herein. An RNA of interest is engineered to contain an URIL and expressed within the cell, with a fluorogenic bPNA probe introduced via cell culture media. Successful URIL targeting is reported by an increase in emission (green) and confirmed by a previously established RNA binding protein with a fluorescent protein (red) fusion. C_FIG

cell biology↗

bioRxiv2021

Nanotrap Particles Improve Nanopore Sequencing of SARS-CoV-2 and Other Respiratory Viruses

Presented here is a magnetic hydrogel particle enabled workflow for capturing and concentrating SARS-CoV-2 from diagnostic remnant swab samples that significantly improves sequencing results using the Oxford Nanopore Technologies MinION sequencing platform. Our approach utilizes a novel affinity-based magnetic hydrogel particle, circumventing low input sample volumes and allowing for both rapid manual and automated high throughput workflows that are compatible with nanopore sequencing. This approach enhances standard RNA extraction protocols, providing up to 40x improvements in viral mapped reads, and improves sequencing coverage by 20-80% from lower titer diagnostic remnant samples. Furthermore, we demonstrate that this approach works for contrived influenza virus and respiratory syncytial virus samples, suggesting that it can be used to identify and improve sequencing results of multiple viruses in VTM samples. These methods can be performed manually or on a KingFisher Apex system.

microbiology↗

bioRxiv2020

Nanotrap(R) particles improve detection of SARS-CoV-2 for pooled sample methods, extraction-free saliva methods, and extraction-free medium methods

Here we present a rapid and versatile method for capturing and concentrating SARS-CoV-2 from transport medium and saliva using affinity-capture magnetic hydrogel particles. We demonstrate that the method concentrates virus prior to RNA extraction, thus significantly improving detection of the virus using a real-time RT-PCR assay across a range of viral titers, from 100 to 1,000,000 viral copies/mL; in particular, detection of virus in low viral load samples is enhanced when using the method coupled with the IDT 2019-nCoV CDC EUA Kit. This method is compatible with commercially available nucleic acid extraction kits, as well with a simple heat and detergent method. Using transport medium diagnostic remnant samples that previously had been tested for SARS-CoV-2 using either the Abbott RealTime SARS-CoV-2 EUA Test (n=14) or the Cepheid Xpert Xpress SARS-CoV-2 EUA Test (n=35), we demonstrate that our method not only correctly identifies all positive samples (n = 17) but also significantly improves detection of the virus in low viral load samples. The average improvement in cycle threshold (Ct) value as measured with the IDT 2019-nCoV CDC EUA Kit was 3.1; n = 10. Finally, to demonstrate that the method could potentially be used to enable pooled testing, we spiked infectious virus or a confirmed positive diagnostic remnant sample into 5 mL and 10 mL of negative transport medium and observed significant improvement in the detection of the virus from those larger sample volumes.

microbiology↗

bioRxiv2019

Active monomer RTR-1 derived from the root of Rhodomyrtus tomentosa induces apoptosis in gastric carcinoma cells by inducing ER stress and inhibiting the STAT3 signalling pathway

ObjectiveRhodomyrtus tomentosa, a flowering plant belonging to the Myrtaceae family, is considered an antitumour substance with versatile biological and pharmacological activities. And RTR-1 is an active monomer purified from the root of Rhodomyrtus tomentosa. However, the detail of the mechanisms of anti-cancer activity of RTR-1 remains to be elucidated and the effect on gastric cancer cells is unknown. MethodsCell proliferation was determined by MTT and clone formation assay. The effect of RTR-1 on cell cycle and apoptosis was analyzed utilizing flow cytometry, respectively. Moreover, western blotting was used to detect the expression of cell cycle- and apoptosis-related protein. ResultsBased on MTT and clone formation assay, we noticed that RTR-1 inhibited the proliferation of gastric carcinoma (BGC823 and SGC7901) cells in a dose- and time-dependent manner. Furthermore, the results of flow cytometry and western blotting showed that RTR-1 induced cell cycle arrest in the G2/M phase through the ATM-Chk2-p53-p21 signalling pathway and induced cell apoptosis by inhibiting the signal transducers and activators of transcription 3 (STAT3) pathway and activating the endoplasmic reticulum stress (ER stress) pathway. ConclusionTaken together, these results demonstrate that RTR-1 induces cell cycle arrest and promotes apoptosis in gastric carcinoma, indicating its potential application for gastric cancer therapy.

cancer biology↗