bioRxiv Science⌕ Search

Biology subjects

Qu, N.

Publications and source records attributed to Qu, N..

6 recordsLinked to original sources

A microbiota-derived protease links phage susceptibility to host epithelial responses

Bacteriophages are major ecological drivers of gut microbial ecology, yet whether bacterial mechanisms that determine phage susceptibility have consequences for the mammalian host remains poorly understood. Here, we identify dipeptidyl peptidase 11 (Dpp11a), the predominant active serine protease of the prevalent gut commensal Phocaeicola vulgatus, as an unexpected bacterial defence factor. Dpp11a protects against environmental proteases and confers resistance to bacteriophage infection. Metatranscriptomic analyses further reveal increased expression of both dpp11a and P. vulgatus-associated phage transcripts in ulcerative colitis stool samples, indicating that both components of this interaction are transcriptionally active in disease-associated human microbiomes. Using the microfluidic gut-on-a-chip co-culture model HuMiX, we show that the absence of Dpp11 is accompanied by altered epithelial tight-junction remodelling during phage-bacterial infection. Together, our findings reveal that the consequences of bacterial phage defence can extend beyond phage-bacterium interactions to the mammalian epithelium.

microbiology↗

Novel lentiviral constructs for the specification of rare and ectopic cell types in human colonoids.

Human colonoids derived from adult intestinal tissue provide powerful models for epithelial biology but lack several rare or regionally restricted cell types. To overcome this limitation, we engineered doxycycline-inducible lentiviral constructs to drive expression of transcription factors that control lineage specification, including KLF4, POU2F3, SPIB, NEUROG3, and NEUROG3 T2A NKX6-3. Transduction of human colonoids with these constructs revealed that transient KLF4 induction is sufficient to generate TFF3 and WFDC2 expressing goblet cells. Unexpectedly KLF4 also induced GUCA2A positive colonocytes. In contrast, SPIB and POU2F3 were not sufficient to specify M-cells or mature tuft cells respectively, suggesting the requirement for additional permissive cues. Notably, co-expression of NEUROG3 and NKX6-3 induced enteroendocrine subtypes characteristic of the duodenum. These findings establish a set of lentiviral tools for induction of specific epithelial lineages in human colonoids providing a platform for replenishing cell types that are lost or altered in intestinal diseases.

cell biology↗

Identify compound-protein interaction with knowledge graph embedding of perturbation transcriptomics

The emergence of perturbation transcriptomics provides a new perspective and opportunity for drug discovery, but existing analysis methods suffer from inadequate performance and limited applicability. In this work, we present PertKGE, a method designed to improve compound-protein interaction with knowledge graph embedding of perturbation transcriptomics. PertKGE incorporates diverse regulatory elements and accounts for multi-level regulatory events within biological systems, leading to significant improvements compared to existing baselines in two critical "cold-start" settings: inferring binding targets for new compounds and conducting virtual ligand screening for new targets. We further demonstrate the pivotal role of incorporating multi- level regulatory events in alleviating dataset bias. Notably, it enables the identification of ectonucleotide pyrophosphatase/phosphodiesterase-1 as the target responsible for the unique anti- tumor immunotherapy effect of tankyrase inhibitor K-756, and the discovery of five novel hits targeting the emerging cancer therapeutic target, aldehyde dehydrogenase 1B1, with a remarkable hit rate of 10.2%. These findings highlight the potential of PertKGE to accelerate drug discovery by elucidating mechanisms of action and identifying novel therapeutic compounds.

bioinformatics↗

Human Pluripotent Stem Cell Derived Organoids Reveal a Role for WNT Signaling in Dorsal-Ventral Patterning of the Hindgut

The cloaca is a transient structure that forms in the terminal hindgut giving rise to the rectum dorsally and the urogenital sinus ventrally. Similarly, human hindgut cultures derived from human pluripotent stem cells generate human colonic organoids (HCOs) which also contain co-developing urothelial tissue. In this study, our goal was to identify pathways involved in cloacal patterning and apply this to human hindgut cultures. RNA-seq data comparing dorsal versus ventral cloaca in e10.5 mice revealed that WNT signaling was elevated in the ventral versus dorsal cloaca. Inhibition of WNT signaling in hindgut cultures biased their differentiation towards a colorectal fate. WNT activation biased differentiation towards a urothelial fate, giving rise to human urothelial organoids (HUOs). HUOs contained cell types present in human urothelial tissue. Based on our results, we propose a mechanism whereby WNT signaling patterns the ventral cloaca, prior to cloacal septation, to give rise to the urogenital sinus.

developmental biology↗

TranSiGen: Deep representation learning of chemical-induced transcriptional profile

With the advancement of high-throughput RNA sequencing technologies, the use of chemical-induced transcriptional profiling has greatly increased in biomedical research. However, the usefulness of transcriptomics data is limited by inherent random noise and technical artefacts that may cause systematical biases. These limitations make it challenging to identify the true signal of perturbation and extract knowledge from the data. In this study, we propose a deep generative model called Transcriptional Signatures Generator (TranSiGen), which aims to denoise and reconstruct transcriptional profiles through self-supervised representation learning.TranSiGen uses cell basal gene expression and compound molecular structure representation to infer the chemical-induced transcriptional profile. Results demonstrate the effectiveness of TranSiGen in learning and predicting differential expression genes. The representation derived from TranSiGen can also serve as an alternative phenotype information, with applications in ligand-based virtual screening, drug response prediction, and phenotype-based drug repurposing. We envisage that integrating TranSiGen into the drug discovery and mechanism research pipeline will promote the development of biomedicine.

bioinformatics↗

TERT accelerates BRAF mutant-induced thyroid cancer dedifferentiation and progression by regulating ribosome biogenesis

TERT reactivation occurs frequently in human malignancies. While BRAF activating mutation widely existed in cancers at various stages, TERT reactivation mainly occurs in advanced tumors. However, in vivo evidence for TERT role in cancer progression and the underlying mechanism is currently lacking. In this study, we induced TERT and/or BRAF V600E expression in mouse thyroid epithelium. TERT overexpression alone had no evident effect on tumor initiation. BRAFVE expression itself induced mediocre papillary thyroid cancer (PTC). Notably, the co-expression of BRAFVE and TERT resulted in aggressive poorly differentiated thyroid carcinoma (PDTC). Spatial transcriptome revealed that tumors from co-mutant mice were highly heterogeneous and dedifferentiation process significantly correlated with ribosomal pathways. Mechanistically, TERT boosted ribosomal RNA expression and protein synthesis. CX-5461, a rRNA transcription inhibitor, effectively blocked proliferation and induced redifferentiation. Thus, TERT promotes thyroid cancer progression by inducing dedifferentiation, and ribosome biogenesis inhibition represents a potential treatment strategy for TERT-reactivated cancers. Highlights[tpltrtarr] TERT accelerated thyroid cancer dedifferentiation and metastasis in vivo [tpltrtarr]TERT regulated rRNA metabolism and MTORC1/ S6K/RPS6 activities [tpltrtarr]CX-5461 inhibited the progression of TERT-reactivated melanoma and thyroid cancer [tpltrtarr]Inhibition of rRNA induced redifferentiation of advanced thyroid cancer with TERT activation

cancer biology↗