Biology subjects

Wasserberg, N.

Publications and source records attributed to Wasserberg, N..

3 recordsLinked to original sources

bioRxiv2024

Discordant effects of ex-vivo JAK inhibition on inflammatory responses in colonic compared to ileal mucosa

Background & aimsJanus kinase (JAK) inhibitors modulating JAK-STAT (signal transducers and activators of transcription) signaling pathway, are used for the treatment of patients with inflammatory bowel diseases (IBD). We aimed to identify the molecular effects of JAK inhibition in the human intestinal mucosa, considering the IBD location and phenotype. MethodsColonic and ileal explants from patients with ulcerative colitis (UC), Crohns disease (CD), or non-IBD controls (NC) were treated ex-vivo with the JAK inhibitor, tofacitinib. Phosphorylated STAT (p-STAT) levels were assessed by Western blot and Immunofluorescence. Inflammatory genes expression was assessed with Nanostring nCounter system. Human intestinal organoids were used to assess JAK inhibitors effects on p-STATs and iNOS expression. ResultsExplants were collected from 68 patients (NC=28; UC=20; CD=20). JAK inhibition reduced p-STAT1/3/5 expression in all explants. While p-STAT inhibition rates varied among patients (10%-88%), higher inhibition rates were observed in colonic compared to ileal explants. Significant alterations in 120 of 255 inflammatory genes were observed in colonic explants, while only 30 were observed in ileal NC explants. In colonic explants from UC, significant alterations were observed in 5 genes, including STAT1 and NOS2. Various JAK inhibitors reduced IFN-{gamma}-induced increase in p-STAT1 and iNOS expression in organoids. ConclusionsA site-specific anti-inflammatory effect of JAK inhibition by tofacitinib was noticed, whereby the colon was more robustly affected than the ileum. Ex-vivo response to tofacitinib is individual. JAK inhibition may attenuate inflammation by decreasing iNOS expression. Ex-vivo mucosal platforms may be a valuable resource for studying drug impact and evaluating personalized treatment effects.

immunology↗

bioRxiv2022

Human intestinal epithelial cells can internalize luminal fungi via LC3-associated phagocytosis

Intestinal epithelial cells (IECs) are the first to encounter luminal microorganisms and actively participate in intestinal immunity. We reported that IECs express the {beta}-glucan receptor Dectin-1, and respond to commensal fungi and {beta}-glucans. In phagocytes, Dectin-1 mediates LC3 associated phagocytosis (LAP) utilizing autophagy components to process extracellular cargo. Dectin-1 can mediate phagocytosis of {beta}-glucan-containing particles by non-phagocytic cells. We aimed to determine whether human IECs phagocytose {beta}-glucan-containing fungal particles via LAP. Zymosan ({beta}-glucan particle) and Heat-killed and UV inactivated C. albicans were phagocytosed by monolayers of human colonic (n=18) and ileal (n=4) organoids and IEC lines. LAP was identified by LC3 and Rubicon recruitment to phagosomes and lysosomal processing of internalized particles was demonstrated by co-localization with lysosomal dyes and LAMP2. Phagocytosis was significantly diminished by blockade of Dectin-1, actin polymerization and NAPDH oxidases. Our results show that human IECs sense luminal fungal particles and internalize them via LAP. This novel mechanism of luminal sampling suggests that IECs may contribute to the maintenance of mucosal tolerance towards commensal fungi.

immunology↗

bioRxiv2021

Escherichia coli strains from patients with inflammatory bowel diseases have disease-specific genomic adaptations

ObjectiveEscherichia coli is over-abundant in the gut microbiome of patients with IBD, yet most studies have focused on the adherent-invasive E. coli pathotype. Here, we aimed to identify IBD-specific or phenotype-specific genomic functions of diverse E. coli lineages. DesignWe investigated E. coli from patients with UC, CD and a pouch and healthy subjects. The majority of E. coli genomes were reconstructed directly from metagenomic samples, including publicly available and newly sequenced fecal metagenomes. Clinical metadata and biomarkers were collected. Functional analysis at the gene and mutation level and genome replication rates of E. coli strains were performed, and correlated with IBD phenotypes and biomarkers. ResultsOverall, 530 E. coli genomes were analysed. A specific E. coli lineage (B2) was more prevalent in UC compared to other IBD phenotypes. Genomic metabolic capacities varied across E. coli lineages and IBD phenotypes. Specifically, sialidases involved in host mucin utilization, were exclusively present in a single lineage and were depleted in patients with a pouch. In contrast, enzymes that hydrolyze inulin were enriched in patients with a pouch. E. coli from patients with UC were twice as likely to encode the genotoxic molecule colibactin than strains from patients with CD or pouch. Strikingly, patients with a pouch showed the highest E. coli growth rates, even in the presence of antibiotics. Fecal calprotectin did not correlate with the relative abundance of E. coli. Finally, we identified multiple IBD-specific loss-of function mutations in E. coli genes encoding for bacterial cell envelope and secretion components. ConclusionThis study presents E. coli as a commensal species better adapted to the overly-active mucosal immune milieu in IBD, that may benefit from intestinal inflammation, rather than causing it. The evidence given here suggests adaptive evolution toward attenuated virulence in some E. coli strains, coupled with a rapid growth despite the presence of antibiotics.

genomics↗