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Cao, L.

Publications and source records attributed to Cao, L..

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Profiling Siglec-7 and Siglec-9 ligands across the LuCaP PDX series: Implications for glyco-immune checkpoint inhibition in advanced prostate cancer

Advanced prostate cancer exhibits profound cellular and molecular heterogeneity, frequently becoming resistant to androgen receptor (AR) targeting through lineage plasticity and neuroendocrine differentiation. Immunotherapies have shown limited efficacy in prostate cancer, largely due to its immunosuppressive tumour microenvironment. Hypersialylation contributes to immune evasion by engaging sialic acid-binding immunoglobulin-like lectins (Siglecs) on immune cells, forming glyco-immune checkpoints. Although this pathway represents a promising therapeutic target, the distribution of Siglec ligands across diverse prostate cancer phenotypes and their response to standard-of-care hormone therapy remain poorly understood. Here, we utilised high-affinity engineered sialoglycan-binding reagents (HYDRA) to perform comprehensive immunohistochemical profiling of Siglec-7 and Siglec-9 ligands across a panel of 40 Washington Carcinoma of the Prostate (LuCaP) patient-derived xenograft (PDX) models. Ligand expression was evaluated in relation to AR status and neuroendocrine phenotype. To determine the impact of androgen deprivation on the tumour glycome, ligand expression was compared between matched PDX lines grown in intact and castrated mice. Our findings reveal widespread but heterogeneous expression of Siglec-7 and Siglec-9 ligands across the LuCaP cohort. Expression levels were comparable between AR-positive adenocarcinoma models and AR-negative neuroendocrine variants, demonstrating that this glyco-immune checkpoint is maintained across distinct prostate cancer lineages. Under castration conditions, glycan remodelling occurred in a model-dependent manner. A subset of PDX models exhibited reduced Siglec ligand expression following castration, suggesting partial AR dependence. In contrast, other models displayed increased ligand expression, consistent with adaptive immune evasion in response to therapeutic stress, while a third group remained largely unchanged. Collectively, our study demonstrates that the Siglec-7/9 glyco-immune checkpoint axis is broadly maintained across the spectrum of prostate cancer lineage plasticity but is dynamically remodelled by androgen deprivation in a patient-specific manner. These findings support the sialoglycan-Siglec axis as a lineage-independent immunotherapeutic target and suggest that strategies aimed at disrupting Siglec-mediated immune suppression, such as tumour desialylation, may be most effective when combined with androgen deprivation therapy to enhance anti-tumour immunity.

cancer biology

Increased influence of periphery on central visual processing in humans during walking

Cognitive processes are almost exclusively investigated under highly controlled settings while voluntary body movements are suppressed. However, recent animal work suggests differences in sensory processing between movement states by showing drastically changed neural responses in early visual areas between locomotion and stillness. Does locomotion also modulate visual cortical activity in humans and what are its perceptual consequences? Here, we present converging neurophysiological and behavioural evidence that walking leads to an increased influence of peripheral stimuli on central visual input. This modulation of visual processing due to walking is encompassed by a change in alpha oscillations, which is suggestive of an attentional shift to the periphery during walking. Overall, our study shows that strategies of sensory information processing can differ between movement states. This finding further demonstrates that a comprehensive understanding of human perception and cognition critically depends on the consideration of natural behaviour.

neuroscience

Regulatory networks of gene expression in maize (Zea mays) under drought stress and re-watering

Drought can severely limit plant growth and production. However, few studies have investigated gene expression profiles in maize during drought/re-watering. We compared drought-treated and water-sufficient maize plants by measuring their leaf relative water content, superoxide dismutase and peroxidase activities, proline content, and leaf gas exchange parameters (photosynthetic rates, stomatal conductance, and transpiration rates). We conducted RNA sequencing analyses to elucidate gene expression profiles and identify miRNAs that might be related to drought resistance. A GO enrichment analysis showed that the common DEGs (differently expressed genes) between drought-treated and control plants were involved in response to stimulus, cellular process, metabolic process, cell part, and binding and catalytic activity. Analyses of gene expression profiles revealed that 26 of the DEGs under drought encoded 10 enzymes involved in proline synthesis, suggesting that increased proline synthesis was a key part of the drought response. We also investigated cell wall-related genes and transcription factors regulating abscisic acid-dependent and -independent pathways. The expression profiles of the miRNAs miR6214-3p, miR5072-3p, zma-miR529-5p, zma-miR167e-5p, zma-miR167f-5p, and zma-miR167j-5p and their relevant targets under drought conditions were analyzed. These results provide new insights into the molecular mechanisms of drought tolerance, and may identify new targets for breeding drought-tolerant maize lines.\n\nAbbreviationsleaf relative water content: RWC, superoxide dismutase activity: SOD, peroxidase activity: POD, proline content: Pro, photosynthetic rates: Pn, stomatal conductance: Cond, transpiration rates: Tr.; quantitative real-time polymerase chain reaction: qPCR; abscisic acid; ABA; polyethylene glycol :PEG; Principal component analysis :PCA; polyacrylamide gel electrophoresis :PAGE\n\nHighlightThe study of physiology and molecular mechanism of maize laid a theoretical foundation for drought resistance breeding under drought stress and re-watering.

genomics

Nicastrin haploinsufficiency alters expression of type-I interferon-stimulated genes in two immortalized human cell lines

A.BackgroundHidradenitis suppurativa (HS) is a chronic skin disease. The symptoms can be severe, and include intensely painful nodules and abscesses in apocrine-gland rich inverse skin, such as the buttocks, under the arms, and the groin. Autosomal dominant forms of HS exist, but are rare. Some of these kindred have heterozygous loss-of-function rare variants in the {gamma}-secretase complex component nicastrin (NCSTN).\n\nObjectivesWe wanted to know what effect NCSTN haploinsufficiency has on human keratinocytes to assess potential mechanisms for lesion development.\n\nMethodsWe knocked down nicastrin using an shRNA construct in both a keratinocyte cell line (HEK001) and an embryonic kidney cell line (HEK293). We assessed differential gene expression using RNA microarray. We also generated a NCSTN heterozygous deletion in the HEK293 line using CRISPR/Cas9 genome-editing and assessed NFKB activity in this line using a luciferase reporter.\n\nResultsThe keratinocyte NCSTN knockdown cell line demonstrated significantly increased expression of genes related to the type-I interferon response pathway when compared to controls. Both HEK001 and HEK293 knockdowns demonstrated evidence for altered growth. We observed a small, but significant increase in NFKB signaling in response to TNF treatment a HEK293 line genome-edited for reduced NCSTN.\n\nConclusionsOur data suggest a role for increased keratinocyte inflammatory responsiveness in familial HS. Confirming this phenotype, and characterizing additional effects in different cell types, will require study beyond cell lines in primary cells and tissues.

cell biology

Genome-encoded Cytoplasmic Double-Stranded RNAs, Found in C9ORF72 ALS-FTD Brain, Provoke Propagated Neuronal Death

Innate immune signaling activation and DNA damage are pathological hallmarks of aging that may herald multiple adult-onset neurodegenerative diseases. Here, we report that both cell autonomous and non-autonomous neuronal death are triggered by the production of cytoplasmic double-stranded RNA (cdsRNA) from a regulated, disarticulated transgene in the setting of type I interferon (IFN-I) signaling. CdsRNA is a pathogen associated molecular pattern that induces IFN-I in many cell types. Transfection of a dsRNA mimetic into cultured human neurons also induces IFN-I signaling and cell death in a dose-dependent manner. Direct relevance to human disease is found in neurons of ALS-FTD patients carrying C9ORF72 intronic hexanucleotide expansions; cdsRNA isolated from these tissues is comprised of repeat sequences. Together, these findings implicate cdsRNA generated from genomic sequences in neurons as a trigger for sterile, viral-mimetic IFN-I induction and propagated neuronal death within in a neural circuit in the aging nervous system.

neuroscience

Modulation of formin processivity by profilin and mechanical tension

Formins are major regulators of actin networks. They enhance actin filament dynamics by remaining processively bound to filament barbed ends. How biochemical and mechanical factors affect formin processivity are open questions. Monitoring individual actin filaments in a microfluidic flow, we report that formin mDia1 dissociates faster under higher ionic strength and when actin concentration is increased. Profilin, known to increase the elongation rate of formin-associated filaments, surprisingly decreases the formin dissociation rate, by bringing formin FH1 domains in transient contact with the barbed end. In contrast, piconewton tensile forces applied to actin filaments accelerate formin dissociation by orders of magnitude, largely overcoming profilin-mediated stabilization. We developed a model of formin conformations and its confrontation to our data indicates the existence of two different dissociation pathways, with force favoring one over the other. How cells limit formin dissociation under tension is now a key question for future studies.

biophysics

GVC: A superfast and universal genomic variant caller

Germline and somatic variant detection from human and cancer whole-genome sequencing data is a challenge task for genome-wide association study and cancer genomics in precision medicine. Many confounding factors contribute the difficulties including complexity of variant, sequencing and alignment error, tumor clonality and sample purity etc. Current genomic variant callers are too time-consuming to meet the requirement of clinical application in precision medicine. We developed superfast and universal Genomic Variant Caller (GVC), which can simultaneously detect various genomic variants including SNV, sINDEL and SV from personal and normal-cancer paired whole-genome/exome sequencing data within fifteen minutes. Whats more, it achieved higher sensitivity and precision than popular variant callers including GATK4, Mutect, NovoBreak in germline and somatic variant detection from NA12878 and ICGC-TCGA Dream Challenge Datasets respectuvely. It is worth mentioning that GVC achieved comparable performance in variant detection from NA12878 sequenced by three different high-throughput sequencing platforms including Illumina HiSeq2000, NovaSeq and BGISEQ-500.

bioinformatics

Molecular and functional variation in iPSC-derived sensory neurons

Induced pluripotent stem cells (iPSCs), and cells derived from them, have become key tools to model biological processes and disease mechanisms, particularly in cell types such as neurons that are difficult to access from living donors. Here, we present the first map of regulatory variants in an iPSC-derived cell type. To investigate genetic contributions to human sensory function, we performed 123 differentiations of iPSCs from 103 unique donors to a sensory neuronal fate, and measured gene expression, chromatin accessibility, and neuronal excitability. Compared with primary dorsal root ganglion, where sensory nerves collect near the spinal cord, gene expression was more variable across iPSC-derived neuronal cultures, particularly in genes related to differentiation and nervous system development. Single cell RNA-sequencing revealed that although the majority of cells are neuronal and express the expected marker genes, a substantial fraction have a fibroblast-like expression profile. By applying an allele-specific method we identify 3,778 quantitative trait loci influencing gene expression, 6,318 for chromatin accessibility, and 2,097 for RNA splicing at FDR 10%. A number of these overlap with common disease associations, and suggest candidate causal variants and target genes. These include known causal variants at SNCA for Parkinsons disease and TNFRSF1A for multiple sclerosis, as well as new candidates for migraine, Parkinsons disease, and schizophrenia.

genomics