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Bruland, T.

Publications and source records attributed to Bruland, T..

2 recordsLinked to original sources

JAK and TYK2 inhibitors differentially modulate interferon/TNF-driven inflammation, stemness and proliferation in the colonic epithelium of ulcerative colitis

BackgroundJanus kinase (JAK)-Signal Transducer and Activator of Transcription (STAT) pathway is a key regulator of inflammatory signaling in ulcerative colitis (UC). While most studies have focused on JAK/tyrosine kinase 2 (TYK2) inhibitors effects on immune cell-mediated responses, their direct epithelial impact remains less known. We investigated epithelial-specific transcriptional responses to JAK/TYK2 inhibitors using patient-derived intestinal epithelial organoids (IEOs) under UC-relevant conditions. MethodsColonic IEOs from UC patients were pretreated with various concentrations of tofacitinib, upadacitinib, filgotinib, brepocitinib, and deucravacitinib for 1 hour prior to stimulation with IFN{beta}, IFN{gamma}, or IFN{lambda}1 for Western blot analysis of STAT1/3 and TYK2 phosphorylation. For transcriptomic profiling, IEOs were pretreated with upadacitinib or deucravacitinib for 16 hours, followed by 8-hour stimulation with IFN{gamma}, IFN{lambda}1, TNF, or IFN{gamma} + TNF. Bulk RNA sequencing assessed differential gene expression, and multiplex assays quantified chemokine secretion. Ki67 immunohistochemistry on colonic biopsies from healthy controls, and UC patients with and without JAK inhibitors-treatment were assessed for epithelial proliferation. ResultsIFNs induced distinct STAT1/3 and TYK2 activation, with IFN{beta}/{gamma} eliciting stronger phosphorylation than IFN{lambda}1. All JAK/TYK2 inhibitors regulated pSTAT1/3 and pTYK2, with upadacitinib most strongly inhibiting pSTAT1/3 and deucravacitinib selectively targeting pTYK2. Transcriptomic analysis revealed extensive cytokine-driven gene regulation, with IFN{gamma} + TNF eliciting the strongest response. Enrichment analysis highlighted upregulation of IFN signaling, antigen presentation, and innate immune pathways, alongside downregulation of cell-cycle processes. Drug-response profiling showed minimal transcriptional changes with upadacitinib and deucravacitinib alone. Upadacitinib broadly modulated IFNs and IFN{gamma} + TNF-regulated genes, attenuating JAK-STAT, NF{kappa}B, antiviral, and cell death pathways, while restoring genes linked to mucosal healing. Upadacitinib also reduced IFNs and IFN{gamma} + TNF-driven chemokine genes and protein secretion. In contrast, deucravacitinib showed selective, potent inhibition of inflammatory genes under IFN{lambda}1-stimulation. Both inhibitors minimally impacted TNF-driven pathways. Ki67 immunohistochemistry confirmed enhanced epithelial proliferation in JAK inhibitor-treated UC patients regardless of mucosal inflammation status. ConclusionsOur findings provide novel evidence that JAK/TYK2 inhibitors influence epithelial transcriptional programs associated with inflammation and mucosal healing. Upadacitinib demonstrated broader modulation of cytokine-driven gene networks compared to TYK2-selective inhibition. These findings provide insight into epithelial-specific drug actions and support precision approaches for UC therapy.

molecular biology↗

Transcriptional regulation by NR5A2 couples cell differentiation and inflammation in the pancreas

Tissue-specific differentiation and inflammatory programmes are thought to independently contribute to disease. The orphan nuclear receptor NR5A2 is a key regulator of pancreas differentiation and SNPs in or near the human gene are associated with risk of pancreatic cancer. In mice, Nr5a2 heterozygosity sensitizes the pancreas to damage, impairs regeneration, and cooperates with mutant KRas in tumor progression. Through global transcriptomic analysis, we uncover a basal pre-inflammatory state in the pancreas of Nr5a2 heterozygous mice that is reminiscent of pancreatitis-induced inflammation and is conserved in histologically normal human pancreata with reduced NR5A2 mRNA expression. In Nr5a2+/- mice, Nr5a2 undergoes a dramatic transcriptional switch relocating from tissue-specific to inflammatory loci thereby promoting AP-1-dependent gene transcription. Importantly, deletion of c-Jun in the pancreas of these mice rescues the pre-inflammatory phenotype and the defective regenerative response to damage. These findings provide compelling evidence that the same transcriptional networks supporting homeostasis in normal tissue can be subverted to foster inflammation upon genetic or environmental constraints.

cancer biology↗