Huan, B. | bioRxiv Science

bioRxiv2026

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↗

bioRxiv2025

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↗