Biology subjects

Preglej, T.

Publications and source records attributed to Preglej, T..

6 recordsLinked to original sources

bioRxiv2025

Primulagenin A is a potent inverse agonist of the nuclear receptor RAR-related orphan receptor gamma (RORγ)

Throughout history, herbal medicines and natural products have played a crucial role as therapeutics for humans, yet their molecular mechanisms of action often remain elusive. Here, we ask whether primulagenin A (PGA) from the traditionally used herbal substance Primula root, acts via the nuclear receptor ROR{gamma}, a key regulator of pro-inflammatory Th17 cells, which are linked to autoimmune diseases like psoriasis. Luciferase assays revealed a high potency (IC50 ~100 nM) and efficacy (Imax ~ 90%) of PGA as an inverse agonist of ROR{gamma}. To ensure sufficient supply, we established methods to isolate and synthesize PGA. Its binding to the human ROR{gamma} ligand binding domain was confirmed by nano differential scanning fluorimetry, and a structure-activity relationship was proposed by docking and site-directed mutagenesis. PGA downregulated ROR{gamma} target gene expression and inhibited murine and human Th17 differentiation in a concentration-dependent manner. It also reduced the proportion of IL-17A-producing Th17 cells. In this work, we identify PGA as a new, potent, and efficacious inverse agonist of ROR{gamma}, with potential for modulating immune responses in inflammatory and autoimmune diseases.

pharmacology and toxicology↗

bioRxiv2025

Targeting histone acetylation enables epigenetic modulation of inflammatory pathways, a novel therapeutic strategy for rheumatoid arthritis

Autoimmune diseases like rheumatoid arthritis (RA) are characterized by a systemic inflammation caused by autoreactive immune cells. Epigenomic modulation of these cells offers a strategy to reprogram pathogenic pathways without altering the genome, potentially restoring immune balance. Epigenetic inhibitors are already utilized in oncology but often exhibit adverse effects due to lack of selectivity and cytotoxic concentrations. Applying these drugs to treat autoimmune diseases necessitates more selective inhibitors and the use of tolerable concentrations. In this study, we screened a library of 25 compounds with varying degrees of target selectivity and different concentrations. Spectral cytometry enabled the analysis of cell-subset distribution and activation, followed by bulk RNA-sequencing for transcriptomic profiling. We could demonstrate cell-subset specific and concentration-dependent immune modulation in PBMCs. Transcriptomic analysis showed that inhibitors of histone acetylation-modulating enzymes significantly altered gene expression, particularly in immune regulation pathways relevant to autoimmune diseases. Comparative analysis between in-vitro treated healthy controls and RA patients demonstrated both shared and selective drug effects, with some inhibitors like Ricolinostat overlapping with established RA drug pathways. Our findings highlight the potential of epigenetic inhibitors, especially those targeting histone acetylation, to modulate immune responses in a target-selective manner. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/632975v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@30f4faorg.highwire.dtl.DTLVardef@23578borg.highwire.dtl.DTLVardef@4890ceorg.highwire.dtl.DTLVardef@1acbb5_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Time-resolved immune dynamics in rheumatoid arthritis under Methotrexate therapy

Rheumatoid arthritis (RA) is characterized by immune dysregulation, including alterations in peripheral blood mononuclear cell (PBMC) populations and aberrant cytokine signaling. Methotrexate (MTX) is the preferred first-line treatment for RA, yet its precise mechanisms of action remain incompletely understood. This study employed a multi-omics strategy--combining single-cell RNA sequencing (scRNA-seq) and immunophenotyping--to identify key effector peripheral immune cells and their cellular responses in RA patients over 12 weeks of MTX treatment. In our study, MTX was associated with significant immune modulation, including the restoration of naive T and B cells and reductions in T cell memory subsets with these effects detectable as early as three weeks post-treatment. Plasmablast levels also emerged as a potential biomarker for early therapeutic response, reflecting MTXs impact on immune homeostasis. Transcriptional analysis revealed modulation of key pathways, including TNF- signaling, B cell receptor signaling, and T cell receptor-mediated apoptosis. Network analysis identified critical regulatory hubs, such as EGR1, JAK2, and SOCS1, in monocytes and CD4 memory T cells, highlighting these cell types as key mediators of MTXs effects. In conclusion, these findings advance our understanding of MTXs effects on immune cell dynamics at different stages of treatment, showing for the first time the early cellular changes leading to immune modulation in RA. Altogether, our results provide the foundation for further mechanistic investigations into MTX.

genomics↗

bioRxiv2022

Nuclear receptor corepressor 1 controls regulatory T cell subset differentiation and effector function

FOXP3+ regulatory T cells (Treg cells) are key for immune homeostasis. Here, we reveal that nuclear receptor corepressor 1 (NCOR1) controls naive and effector Treg cell states. Upon NCOR1 deletion in T cells, effector Treg cell frequencies were elevated in mice and in in vitro-generated human Treg cells. NCOR1-deficient Treg cells failed to protect mice from severe weight loss and intestinal inflammation associated with CD4+ T cell transfer colitis, indicating impaired suppressive function. NCOR1 controls transcriptional integrity of Treg cells, since effector gene signatures were already upregulated in naive NCOR1-deficient Treg cells while effector NCOR1-deficient Treg cells failed to repress genes associated with naive Treg cells. Moreover, genes related to cholesterol homeostasis including targets of liver X receptor (LXR) were dysregulated in NCOR1-deficient Treg cells. However, genetic ablation of LXR{beta} in T cells did not revert the effects of NCOR1 deficiency, indicating that NCOR1 controls naive and effector Treg cell subset composition independent from its ability to repress LXR{beta}-induced gene expression. Thus, our study reveals that NCOR1 maintains naive and effector Treg cell states via regulating their transcriptional integrity. We also reveal a critical role for this epigenetic regulator in supporting the suppressive functions of Treg cells in vivo.

immunology↗

bioRxiv2022

24-Nor-ursodeoxycholic acid counteracts TH17/Treg imbalance and ameliorates intestinal inflammation by restricting glutaminolysis in differentiating TH17 cells

Objective24-Nor-ursodeoxycholic acid (NorUDCA) is a novel therapeutic bile acid for treating primary sclerosing cholangitis (PSC), an immune-mediated cholestatic liver disease. Since PSC strongly associates with inflammatory bowel diseases (IBD) driven by TH17/Treg imbalance, we aimed to explore NorUDCAs immunomodulatory potential on intestinal TH17/Treg balance. DesignNorUDCAs impact on TH17/Treg tissue distribution was first assessed in Mdr2-/- mouse model of PSC. We specifically investigated NorUDCAs effect on modulating TH17/Treg balance in a CD4+ T cell driven colitis model induced by adoptive transfer of CD25-CD44lowCD45RBhighCD4+ TNaive cells into Rag2-/- mice, mimicking human IBD. Mechanistic studies were performed using molecular approaches, flow cytometry and metabolic assays in murine TH17 cells in vitro. NorUDCAs signaling effects observed in murine system were further validated in circulating CD4+ T cells from PSC patients with co-existing IBD. ResultsNorUDCA promoted Treg generation in both liver and intestine in the Mdr2-/- model. In the experimental IBD model, NorUDCA attenuated intestinal immunopathology. Mechanistically, NorUDCA demonstrated strong immunomodulatory efficacy in counteracting TH17/Treg imbalance by restricting glutaminolysis in differentiating TH17 cells, thus suppressed -Ketoglutarate-dependent mTORC1 activation, glycolysis and enhanced FOXP3 expression. NorUDCAs impact on mTORC1 signaling was further confirmed in circulating CD4+ T-cells from PSC patients with IBD. ConclusionNorUDCA possesses direct immunometabolic modulatory potency to counteract TH17/Treg imbalance and ameliorate excessive TH17 cell driven intestinal immunopathology. These findings extend future clinical applications of NorUDCA for treatment of TH17 cell-mediated disorders along the gut-liver axis and beyond. Significance of this studyO_ST_ABSWhat is already known on this subject?C_ST_ABSO_LIPSC is an immune-mediated cholestatic liver disease highly associated with IBD where TH17/Treg imbalance drives immunopathogenesis; seeking effective therapeutics covering both liver and intestinal disease in PSC is of high clinical relevance. C_LIO_LIIndependent of anti-cholestatic effects, NorUDCA has recently been shown to possess direct immunomodulatory properties on CD8+ T cell metabolism, lymphoblastogenesis and clonal expansion through targeting mTORC1 signaling. C_LIO_LISince mTORC1 serves as critical metabolic checkpoint orchestrating TH17/Treg axis, inhibiting mTORC1 activity represents a potential treatment avenue counteracting TH17/Treg imbalance under intestinal inflammatory conditions. C_LI What are the new findings?O_LINorUDCA enriches FOXP3+ Treg population in both liver and intestinal tissue in the cholestatic Mdr2-/- mouse model of PSC. C_LIO_LINorUDCA exhibits direct immunomodulatory efficacies in suppressing excess TH17 cell-mediated intestinal immunopathology and promotes FOXP3+ Treg generation in an experimental IBD model. C_LIO_LIMechanistically, NorUDCA counteracts TH17/Treg imbalance by restricting glutaminolysis in differentiating TH17 cells, thus suppresses -Ketoglutarate-dependent mTORC1 activation, glycolysis and enhances FOXP3 expression. C_LIO_LINorUDCAs impact on mTORC1 signaling was further confirmed in circulating CD4+ T cells from patients with PSC and IBD. C_LI How might it impact on clinical practice in the foreseeable future?These findings advance our current understanding of therapeutic potentials of NorUDCA, which might represent a novel therapeutic strategy in the treatment of PSC and concomitant IBD and other TH17-mediated intestinal diseases.

molecular biology↗

bioRxiv2021

24-Nor-Ursodeoxycholic acid reshapes immunometabolism in CD8+ T cells and alleviates hepatic inflammation

Background & Aims24-NorUrsodeoxycholic acid (NorUDCA) is novel therapy for immune-mediated liver diseases such as primary sclerosing cholangitis (PSC) where dysregulated T cells including CD8+ T cells cause liver immunopathology. We hypothesized that NorUDCA may directly modulate CD8+ T cell effector function thus contributing to its therapeutic efficacy independent of anti-cholestatic effects. MethodsNorUDCA effects on CD8+ T cell function in vivo were investigated in a hepatic injury model system induced by excessive CD8+ T cell immune response upon non-cytolytic lymphocytic choriomeningitis virus (LCMV) infection. Mechanistic studies included molecular and biochemical approaches, flow cytometry and metabolic assays in mouse CD8+ T cells in vitro. Mass spectrometry (MS) was used to identify potential targets modulated by NorUDCA in CD8+ T cells. NorUDCA signaling effects observed in murine systems were validated in peripheral T cells from healthy volunteers and PSC patients. ResultsIn vivo NorUDCA ameliorated hepatic injury and systemic inflammation upon LCMV infection. Mechanistically, NorUDCA demonstrated a strong immunomodulatory efficacy in CD8+ T cells affecting lymphoblastogenesis, mTORC1 signaling and glycolysis of CD8+ T cells. With MS, we identified that NorUDCA regulates CD8+ T cells via targeting mTORC1. NorUDCAs impact on mTORC1 signaling was further confirmed in circulating human CD8+ T cells. ConclusionsNorUDCA possesses a yet-unrecognized direct modulatory potency on CD8+ T cells and attenuates excessive CD8+ T cell hepatic immunopathology. These findings may be relevant for treatment of immune-mediated liver diseases such as PSC and beyond.

molecular biology↗