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Biology subjects

Lian, G.

Publications and source records attributed to Lian, G..

11 recordsLinked to original sources

Transcriptome-wide Differential Expression and Splicing in Inflammatory Bowel Disease Patients

The inflammatory bowel diseases (IBD), comprising mainly Crohn's disease (CD) and ulcerative colitis (UC), are characterized by chronic intestinal inflammation driven in part by complex genetic and gene regulatory mechanisms. Although transcriptomic studies have defined broad expression changes in IBD, the contribution of alternative splicing to disease-associated molecular variation remains less clear. We therefore integrated differential expression (DE) and differential splicing (DS) analyses in macroscopically uninvolved colonic mucosal biopsies from patients with either CD or UC along with non-IBD controls to define gene expression and intron-usage changes across disease subtypes. We identified 491 DS and 316 DE genes in CD vs. non-IBD, and 1,298 DS and 1,107 DE genes in UC vs. non-IBD. DS and DE genes were nearly mutually exclusive, with no overlapping genes in CD and 16 in UC. Consistent with this result, pathway analysis showed that differentially expressed and differentially spliced genes were associated with related but distinct biological programs. DE genes were involved in chromatin organization, transcriptional regulation, and metabolic pathways for glycans and drugs, whereas DS genes were enriched for splicing, cellular signaling, and lipid metabolism. We found substantial similarity in enriched pathways across CD and UC with some notable exceptions, including increased enrichment of DS and DE genes involved in extracellular vesicles and exosomes in CD and enrichment of DS genes in ER-to-Golgi trafficking and stress granules in UC. Direct comparisons of CD and UC patients additionally show differential splicing usage in genes involved in cell adhesion pathways. These findings identify alternative splicing as a major contributor to transcriptomic changes in IBD that is largely distinct from changes in expression level and provide a broader view of molecular contributors to IBD.

genomics↗

Development and Analytical Validation of a Smartphone-Based Quantitative Lateral Flow Immunoassay for Serum Cystatin-C

Cystatin-C is an important renal function biomarker, and conventional quantification requires centralized laboratory analyzers, which limits timely testing in primary care and resource-limited settings. To address this need, we developed and validated a simple, rapid, and quantitative smartphone-based (SP) lateral flow immunoassay (LFIA) for measuring serum Cystatin-C. The SP-LFIA platform consists of a colorimetric LFIA strip and a custom SP reader with uniform LED illumination and macro lens for image capture. Quantitative image analysis of the colorimetric signal is performed by a dedicated application using a pre-defined third order polynomial calibration model. Following systematic optimization, the assay demonstrated a wide quantitative range of 0.32-8.00 mg/L, with a limit of detection of 0.15 mg/L. Analytical validation conducted according to CLSI guidelines showed excellent precision, with intra- and inter-assay coefficients of variation below 10%, and no significant interference from bilirubin, triglycerides, hemoglobin, or rheumatoid factor. Accelerated stability testing confirmed robust strip performance after storage at 50 {degrees}C for 28 days. Method comparison using 100 clinical serum samples showed high agreement with a commercial PETIA reference method (R{superscript 2} = 0.993) and minimal bias. These results indicate that the developed smartphone-based LFIA provides a reliable, cost-effective, and practical tool for point-of-care Cystatin-C monitoring.

biochemistry↗

Fatty Acid Oxidation Suppression Reprograms Fibroblasts in Fibrostenotic Crohns Disease

Fibrostenotic complications represent a major cause of morbidity in Crohns disease (CD), yet the cellular mechanisms that drive intestinal fibrosis independent of active inflammation remain poorly understood. Here, we identify impaired fatty acid oxidation (FAO) as a defining metabolic feature of fibroblasts in fibrostenotic CD. Untargeted lipidomics of non-inflamed colonic tissue from CD patients demonstrated enrichment of triacylglycerols and long-chain acylcarnitines, suggesting altered lipid utilization. Across three independent RNA-sequencing cohorts, including treatment-naive pediatric ileal biopsies, FAO genes (CPT1A, CPT2, SLC25A20) were selectively downregulated in patients with or destined to develop fibrostenotic disease. Single-cell RNA-sequencing localized these transcriptional alterations specifically to fibroblasts within strictured ileum. Primary fibroblasts derived from fibrostenotic CD exhibited increased neutral lipid accumulation, impaired mitochondrial fatty acid trafficking, and diminished responsiveness to PPAR{gamma}-mediated suppression of TGF{beta}-induced myofibroblast activation. Together, these findings demonstrate that FAO impairment is a conserved, fibroblast-specific metabolic program associated with intestinal fibrosis in CD and suggest that metabolic modulation of stromal cells represents a potential therapeutic strategy for fibrostenotic disease.

genomics↗

Improving Growth Predictions in Aquaculture through an Improved Bioenergetics Model Incorporating Feed Composition and Nutrient Digestibility for Largemouth Bass (Micropterus salmoides)

Bioenergetics models serve as mechanistic tools to predict growth by linking energy intake, metabolic expenditure, and nutrient partitioning. However, traditional models rely primarily on gross energy (GE) intake, thereby oversimplifying the effects of feed composition and nutrient availability on fish growth. This work therefore proposed a refined bioenergetics model incorporating nutrient-specific digestibility coefficients (ADCs) and feed composition and tested using a compiled dataset (n=235; 165 for calibration and 70 for independent validation) and a field experimental dataset of largemouth bass (Micropterus salmoides). We first optimized parameters of a gross energy intake-based bioenergetics model, increasing R2 from 0.62 to 0.96 and thereby providing a calibrated foundation for subsequent refined model. The refined model demonstrated superior predictive performance on the compiled dataset (R2 = 0.97) with RMSE = 19.86 g and MAE = 10.31 g), representing reductions of 4.13% in RMSE and 19.98% in MAE and a 1.03% increase in R2 compared with the optimized GE-based model. In the field experiment, the refined model achieved high predictive accuracy (R2 = 0.98 and 0.97), whereas the optimized GE-based model showed poor performance (R2 = 0.33 and 0.06 respectively). This study is, to our knowledge, the first bioenergetics framework for largemouth bass that decomposes feed composition and nutrient-specific ADCs to compute macronutrient-resolved digestible energy, enabling formulation-aware growth prediction and nutrient-oriented optimization.

bioengineering↗

Reference-guided Genome Assembly of Long Non-coding RNA Transcripts reveals Target Genes Associated With Crohn's Disease

Crohns disease (CD) is highly heterogeneous in presentation and progression with no cure. Molecular phenotyping has been used to elucidate cellular and tissue-based alterations to characterize drivers and effects of disease. One currently understudied class of functional molecules is long non-coding RNAs (lncRNAs). Studying the full lncRNA landscape in IBD is challenging due in part to an incomplete lncRNA annotation and a lack of their functional characterization in tissues of interest. We used a genome-guided alignment strategy to assemble predicted lncRNA transcripts using short RNA-sequencing data from colon tissue of adult patient samples. When combining our predicted lncRNAs with previous lncRNA annotations, we determined 98 that were differentially expressed, recapitulating many from previous IBD studies while also uncovering new ones. We built gene co-expression networks to cluster lncRNAs with functionally characterized protein-coding genes. Clusters containing differential lncRNAs were correlated to disease status and associated with pathways related to the humoral immune response, metabolism, and tissue regeneration. We uncovered multiple differential lncRNAs whose expression significantly correlated with nearby differential protein-coding genes that have also been differentially expressed in other IBD datasets, such as PITX2. We focused on a predicted lncRNA that is antisense to the PITX2-adjacent lncRNA PANCR, which we called PANCR-AS1, and provide multiple lines of evidence that support PANCR-AS1 functioning as an enhancer of PITX2 expression. Overall, we determined lncRNAs that are potential contributors to CD pathogenesis. We developed a robust pipeline for identifying lncRNAs in diseased and non-diseased tissue that are absent from reference annotations. We also outlined a framework to pinpoint significant disease-associated lncRNAs with potential functional activity related to their nearby protein-coding genes.

genomics↗

Uranium mining fuels evolution in deep groundwater microbiomes

Deep-biosphere microbes have been underpinning global biogeochemical cycles throughout Earth history, yet their evolutionary responses to long-term anthropogenic disturbance remain poorly understood. Neutral-pH in-situ leaching (ISL), the dominant uranium-mining strategy, imposes persistent radiochemical and redox stress offering rare natural experiments across decades for observing subsurface microbial evolution. Here, by exploiting metagenomics and metatranscriptomics in examining microbial responses through various mining stages, we show that neutral U ISL causes substantial changes in microbial communities spanning 2,294 strains accompanied by diversification and selection of active microbial species. These changes occurred during elevated dissolved uranium and radiological activity which correlated with a substantial transcriptional change in energy metabolism, and with an overexpression of specific genes for oxidative-stress defence and DNA-repair pathways. Increased nucleotide diversity in 101 out of 392 species clusters and nonsynonymous/synonymous polymorphism ratios greater than one in 139 species clusters were predominantly observed in metatranscriptomes with elevated radiation, highlighting positive selection of transcriptionally active populations. These findings demonstrate that neutral U ISL drives functional and genetic diversification of subsurface microbiomes, revealing a dynamic and evolutionarily responsive deep biosphere.

genomics↗

eQTL in diseased colon tissue identifies novel target genes associated with IBD

Genome-wide association studies (GWAS) have identified over 300 loci associated with the inflammatory bowel diseases (IBD), but putative causal genes for most are unknown. We conducted the largest disease-focused expression quantitative trait loci (eQTL) analysis using colon tissue from 252 IBD patients to determine genetic effects on gene expression and potential contribution to IBD. Combined with two non-IBD colon eQTL studies, we identified 194 potential target genes for 108 GWAS loci. eQTL in IBD tissue were enriched for IBD GWAS loci colocalizations, provided novel evidence for IBD-associated genes such as ABO and TNFRSF14, and identified additional target genes compared to non-IBD tissue eQTL. IBD-associated eQTL unique to diseased tissue had distinct regulatory and functional characteristics with increased effect sizes. Together, these highlight the importance of eQTL studies in diseased tissue for understanding functional consequences of genetic variants, and elucidating molecular mechanisms and regulation of key genes involved in IBD.

genomics↗

Nociceptive neurons interact directly with gastric cancer cells via a CGRP/Ramp1 axis to promote tumor progression

Cancer cells have been shown to exploit neurons to modulate their survival and growth, including through establishment of neural circuits within the central nervous system (CNS) 1-3. Here, we report a distinct pattern of cancer-nerve interactions between the peripheral nervous system (PNS) and gastric cancer (GC). In multiple GC mouse models, nociceptive nerves demonstrated the greatest degree of nerve expansion in an NGF-dependent manner. Neural tracing identified CGRP+ peptidergic neurons as the primary gastric sensory neurons. Three-dimensional co-culture models showed that sensory neurons directly connect with gastric cancer spheroids through synapse-like structures. Chemogenetic activation of sensory neurons induced the release of calcium into the cytoplasm of cancer cells, promoting tumor growth and metastasis. Pharmacological ablation of sensory neurons or treatment with CGRP inhibitors suppressed tumor growth and extended survival. Depolarization of gastric tumor membranes through in vivo optogenetic activation led to enhanced calcium flux in nodose ganglia and CGRP release, defining a cancer cell-peptidergic neuronal circuit. Together, these findings establish the functional connectivity between cancer and sensory neurons, identifying this pathway as a potential therapeutic target.

cancer biology↗

Aberrant miR-29 is a predictive feature of severe phenotypes in pediatric Crohn's disease

Crohns disease (CD) is a chronic inflammatory gut disorder. Molecular mechanisms underlying the clinical heterogeneity of CD remain poorly understood. MicroRNAs (miRNAs) are important regulators of gut physiology and several have been implicated in the pathogenesis of adult CD. However, there is a dearth of large-scale miRNA studies for pediatric CD. We hypothesized that specific miRNAs uniquely mark pediatric CD. We performed small RNA-sequencing of patient-matched non-inflamed colon and ileum biopsies from treatment-naive pediatric patients with CD (n=169) and a control cohort (n=108). Comprehensive miRNA analysis revealed 58 miRNAs altered in pediatric CD. Notably, multinomial logistic regression analysis revealed that index levels of ileal miR-29 are strongly predictive of severe inflammation and stricturing. Transcriptomic analyses of transgenic mice overexpressing miR-29 show a significant reduction of the tight junction protein gene Pmp22 and classic Paneth cell markers. The dramatic loss of Paneth cells was confirmed by histologic assays. Moreover, we also found that pediatric CD patients with elevated miR-29 exhibit significantly lower Paneth cell counts, increased inflammation scores, and reduced levels of PMP22. These findings strongly indicate that miR-29 up-regulation is a distinguishing feature of pediatric CD, highly predictive of severe phenotypes, and associated with inflammation and Paneth cell loss.

genomics↗

Rice LEAFY COTYLEDON1 hinders photosynthesis in the embryo development to promote seed dormancy

LEAFY COTYLEDON1 (LEC1) is the central regulator of seed development. During seed development, rice embryo photosynthesis is completely blocked, which is different from Arabidopsis green embryo. However, effects of LEC1 on photosynthesis in developing seeds is largely elusive. We generated OsLEC1 mutants using the CRISPR/Cas9 technique. Oslec1 mutant seeds lost the ability of dormancy and triggered photosynthesis in embryos at the early developing stage. Transcriptome analysis demonstrated that Oslec1 mutation promoted photosynthesis and altered diverse hormonal pathways and stress response contributing to seed dormancy. Further, genome-wide identification of OsLEC1 binding sites demonstrated that OsLEC1 directly bound to genes involved in photosynthesis, photomorphogenesis, as well as abscisic acid (ABA) and gibberellin (GA) pathways, in seed maturation. We illustrated an OsLEC1-controlling gene network during seed development, including the interconnection between photosynthesis and ABA/GA biosynthesis/signalling. Our findings suggested that OsLEC1 is an inhibitor of photosynthesis during embryo development to promote rice seed maturation. This study would provide new understanding for the OsLEC1 regulatory mechanisms on photosynthesis in the monocot seed development.

plant biology↗

Single-cell analysis of colonic epithelium reveals unexpected shifts in cellular composition and molecular phenotype in treatment-naiïve adult Crohn's disease

The intestinal epithelial barrier is comprised of a monolayer of specialized intestinal epithelial cells (IECs) that are critical in maintaining gut mucosal homeostasis. Dysfunction within various IEC fractions can increase intestinal permeability, resulting in a chronic and debilitating condition known as Crohns disease (CD). Defining the molecular changes in each IEC type in CD will contribute to an improved understanding of the pathogenic processes and the identification of potential therapeutic targets. Here we performed, for the first time at single-cell resolution, a direct comparison of the colonic epithelial cellular and molecular landscape between treatment-naive adult CD and non-IBD control patients. Our analysis revealed that in CD patients there is a significant skew in the colonic epithelial cellular distribution away from canonical LGR5+ stem cells, located at the crypt-bottom, and toward one specific subtype of mature colonocytes, located at the crypt-top. Further analysis revealed unique changes to gene expression programs in every major cell type, including a previously undescribed suppression in CD of most enteroendocrine driver genes as well as L-cell markers including GCG. We also dissect a previously poorly understood SPIB+ cell cluster, revealing at least four sub-clusters that exhibit unique features. One of these SPIB+ sub-clusters expresses crypt-top colonocyte markers and is significantly up-regulated in CD, whereas another sub-cluster strongly expresses and stains positive for lysozyme (albeit no other canonical Paneth cell marker), which surprisingly is greatly reduced in expression in CD. Finally, through integration with data from genome-wide association studies, we show that genes implicated in CD risk exhibit heretofore unknown cell-type specific patterns of aberrant expression in CD, providing unprecedented insight into the potential biological functions of these genes.

genomics↗