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Zhang, X. D.

Publications and source records attributed to Zhang, X. D..

7 recordsLinked to original sources

A Single-Cell Framework for Classifying Human Th17 Pathogenicity Links Acylcarnitine Metabolism to Non-Pathogenic Inflammation in Type 2 Diabetes

Based on in vitro and animal studies, Th17 cells are classified as pathogenic (pTh17) or non-pathogenic (nTh17), but the inability to identify these subsets in primary human samples limits translation. We developed a single-cell ELISA to enrich human Th17s, enabling transcriptomic and flow-cytometric classification. nTh17 cells predominated in Type 2 diabetes and exhibited signatures of acylcarnitine synthesis, while knockdown of CPT1A demonstrated that acylcarnitine metabolism regulates Th17 pathogenicity.

immunology↗

Comparison of the CDC2-like kinase family across eukaryotes highlights the functional conservation of these unique biological thermometers

The family of CDC2-like kinases (CLKs) play a crucial role in regulating alternative splicing (AS), a process fundamental to eukaryotic gene expression and adaptation. Of particular interest, these enzymes exhibit unique responsiveness to minor temperature shifts, enabling them to modulate AS accordingly. Dysregulated CLK expression is linked to a wide variety of human diseases, establishing them as promising therapeutic targets. Despite the importance of CLKs, limited research has explored the genetic and functional diversification of this gene family. This report investigates the evolutionary origins, diversification, and functional implications of CLKs across major eukaryotic lineages through phylogenetic and structural comparisons. Our data demonstrate these kinases are prevalent throughout eukaryotes, with the original gene (which shares orthology to human CLK2), dating back to the Last Eukaryotic Common Ancestor. We identified three key duplication events in vertebrates, highlighting how this gene family has expanded and diversified in complex metazoans. Despite two instances of CLK paralog loss in vertebrate lineages, CLKs remain prevalent throughout metazoans, suggesting they are essential for complex eukaryotic life. Structural comparisons across diverse eukaryotes demonstrate kinase domain conservation, which is in line with their maintained function in AS regulation. While their N-terminal regions vary significantly in amino acid sequence, the function of this domain to regulate phosphorylation of AS factors is conserved, albeit in a species-specific manner. CLKs exhibit unique thermo-sensitive properties across diverse species, challenging conventional enzymatic behaviour. This temperature regulation, mediated by their kinase activation segment, is characterised by increased activity at lower physiological temperatures. The conservation of this structure, and a thermo-sensitive amino acid motif within it, suggests this was an ancient adaptation for responding to environmental cues. Species-specific temperature profiles highlight the adaptive evolution of CLKs, enabling organisms to thrive in diverse environmental conditions including extreme temperatures. Our analysis expands the understanding of CLK biology across diverse eukaryotes and connects insights from model organisms to human biology.

evolutionary biology↗

The tumour suppressor Fat1 is dispensable for normal murine haematopoiesis

Loss and overexpression of FAT1 occurs among different cancers with these divergent states equated with tumor suppressor and oncogene activity, respectively. Regarding the latter, FAT1 is highly expressed in a high proportion of human acute leukemias relative to normal blood cells, with evidence pointing to an oncogenic role. We hypothesized that this occurrence represents legacy expression of FAT1 in undefined hematopoietic precursor subsets that is sustained following transformation, predicating a role for FAT1 during normal hematopoiesis. We explored this concept by using the Vavi-Cre strain to construct conditional knockout (cKO) mice where Fat1 expression was deleted at the hemopoietic stem cell stage. Extensive analysis of precursor and mature blood populations using multi-panel flow cytometry revealed no ostensible differences between Fat1 cKO mice and normal littermates. Further functional comparisons involving colony forming unit and competitive bone marrow transplantation assays support the conclusion that Fat1 is dispensable for normal murine haematopoiesis.

cancer biology↗

High-sensitivity whole-genome recovery of single viral species in environmental samples

Characterizing unknown viruses is essential for understanding viral ecology and preparing against viral outbreaks. Recovering complete genome sequences from environmental samples remains computationally challenging using metagenomics, especially for low-abundance species with uneven coverage. This work presents a method for reliably recovering complete viral genomes from complex environmental samples. Individual genomes are encapsulated into droplets and amplified using multiple displacement amplification. A novel gene detection assay, which employs an RNA-based probe and an exonuclease, selectively identifies droplets containing the target viral genome. Labeled droplets are sorted using a microfluidic sorter, and genomes are extracted for sequencing. Validation experiments using a sewage sample spiked with two known viruses demonstrate the methods efficacy. We achieve 100% recovery of the spiked-in SV40 (Simian virus 40, 5243bp) genome sequence with uniform coverage distribution, and approximately 99.4% for the larger HAd5 genome (Human Adenovirus 5, 35938bp). Notably, genome recovery is achieved with as few as one sorted droplet, which enables the recovery of any desired genomes in complex environmental samples, regardless of their abundance. This method enables targeted characterizations of rare viral species and whole-genome amplification of single genomes for accessing the mutational profile in single virus genomes, contributing to an improved understanding of viral ecology.

bioengineering↗

The pan-cancer lncRNA PLANE regulates an alternative splicing program to promote cancer pathogenesis

Genomic amplification of the distal portion of chromosome 3q, which encodes a number of oncogenic proteins, is one of the most frequent chromosomal abnormalities in malignancy. Here we functionally characterise a non-protein product of the 3q region, the long noncoding RNA (lncRNA) PLANE, which is upregulated in diverse cancer types through copy number gain as well as E2F1-mediated transcriptional activation. PLANE forms an RNA-RNA duplex with the nuclear receptor co-repressor 2 (NCOR2) pre-mRNA at intron 45, binds to heterogeneous ribonucleoprotein M (hnRNPM) and facilitates the association of hnRNPM with the intron, thus leading to repression of the alternative splicing (AS) event generating NCOR2-202, a major protein-coding NCOR2 AS variant. In consequence, PLANE promotes cancer cell proliferation and tumorigenicity and its upregulation is associated with poor patient outcomes. These results uncover the function and regulation of PLANE and suggest that PLANE may constitute a therapeutic target in the pan-cancer context.

cancer biology↗

LncRNA GUARDIN suppresses cellular senescence through a LRP130-PGC1α-FOXO4-p21-dependent signaling axis

The long non-coding RNA GUARDIN functions to protect genome stability. Inhibiting GUARDIN expression can alter cell fate decisions towards senescence or apoptosis, but the underlying molecular signals are unknown. Here we show that GUARDIN is an essential component of a transcriptional repressor complex involving LRP130 and PGC1 which suppresses FOXO4 expression. GUARDIN acts as a scaffold to stabilize LRP130/PGC1 heterodimers and their occupancy at the FOXO4 promotor. Destabilizing this complex by silencing of GUARDIN, LRP130 or PGC1 leads to FOXO4-dependent upregulation of p21, thereby driving cells into senescence. We also found that GUARDIN expression was induced by rapamycin, a senolytic agent that suppresses cell senescence. FOS-Like Antigen 2 (FOSL2) acts as a transcriptional repressor of GUARDIN with increased levels in the presence of rapamycin resulting from downregulation of FOSL2. Together, these results demonstrate that GUARDIN inhibits p21-dependent senescence through a LRP130-PGC1-FOXO4 signaling axis and moreover, GUARDIN contributes to the anti-senolytic activities of rapamycin.

cell biology↗

The lncRNAs Implicated in Redox Regulation in Ybx1 Deficient Zebrafish Larvae

Ybx1 has been demonstrated as a crucial gene in embryogenesis, reproduction as well as development in various vertebrates such as mouse and zebrafish. However, the underlying lncRNA-mediated mechanisms require deep investigation. Particularly, the importance of lncRNA to vertebrate development is controversial and questionable since many studies have yielded contradictory conclusions for the same lncRNAs. In the present study, in order to disclose the lncRNAs implicated in vertebrate development, a systematic transcriptome analysis is conducted based on the RNA sequencing data derived from ybx1 homozygous mutant zebrafish on day5 (day5_ybx1-/-) as well as wild type zebrafish on day5 and day6 (day5_ybx1+/+, day6_ybx1+/+). A high-confidence dataset of zebrafish lncRNAs is detected using a stepwise filtering pipeline. Differential expression analysis and co-expression network analysis reveal that several lncRNAs probably act on duox and noxo1a, the genes related to redox (reduction-oxidation reaction) processes which are triggered by ybx1 disruption. Validation by an experimental study on three selected lncRNAs indicates that knockdown of all selected lncRNAs leads to morphological deformation of larvae. In addition, our experiments effectively support the prediction of network analysis in many interaction patterns between the selected lncRNAs and the two redox genes (duox, noxo1a). In short, our study provides new insights into the function and mechanism of lncRNAs implicated in zebrafish embryonic development and demonstrates the importance of lncRNAs in vertebrate development.\n\nAuthor SummaryLncRNAs has been emerged as key regulatory layers because of their multiple functions in diverse biological processes and pathways. However, there is disagreement about the roles of lncRNAs in vertebrate development Some cases demonstrated that lncRNAs was important to development. Others showed that lncRNAs just have feeble functions in development. On the other hand, Ybx1 processing multi-functions has been well demonstrated as a key protein to most vertebrate in development. Hence, aimed at disclosure of key lncRNAs implicated in vertebrate development as well as their possible roles, we performed a systematic transcriptome analysis based on the deep RNA sequencing data of ybx1 homozygous mutant zebrafish and wild type zebrafish. Our analysis successfully revealed several lncRNAs probably target on the redox-related genes. Furthermore, our experiments validated the importance of these lncRNAs to zebrafish embryo development. This study is the first to utilize Ybx1 as breakpoint to identify key lncRNA related to vertebrate development and provides new insights into underlying mechanisms of lncRNAs in development.

developmental biology↗