Liesbeth Allais

Over Liesbeth

Werkervaring

1. Veterinair Labodeskundige

   Dierengezondheidszorg Vlaanderen · 2016 – heden

2. PhD

   Universiteit Gent · 2011 – 2016

Opleiding

• Master of Science Biochemie & Biotechnologie

  Universiteit Gent · 2010

• Doctoraat in de Medische Wetenschappen

  Universiteit Gent · 2016

Onderzoek

• Cigarette smoking and inflammatory bowel disease: insights into microbial and immune homeostasis

  PhD Thesis. · 2016

• Translational research into the effects of cigarette smoke on inflammatory mediators and epithelial TRPV1 in Crohn’s disease

  2020

  Crohn's disease is a pathological condition of the gastro-intestinal tract, causing severe transmural inflammation in the ileum and/or colon. Cigarette smoking is one of the best known environmental risk factors for the development of Crohn's disease. Nevertheless, very little is known about the effect of prolonged cigarette smoke exposure on inflammatory modulators in the gut. We examined the effect of cigarette smoke on cytokine profiles in the healthy and inflamed gut of human subjects and in the trinitrobenzene sulphonic acid mouse model, which mimics distal Crohn-like colitis. In addition, the effect of cigarette smoke on epithelial expression of transient receptor potential channels and their concurrent increase with cigarette smoke-augmented cytokine production was investigated. Active smoking was associated with increasedIL-8transcription in ileum of controls (p < 0,001; n = 18-20/group). In the ileum, TRPV1 mRNA levels were decreased in never smoking Crohn's disease patients compared to healthy subjects (p <0,001; n = 20/group). In the colon, TRPV1 mRNA levels were decreased (p = 0,046) in smoking healthy controls (n = 20/group). Likewise, healthy mice chronically exposed to cigarette smoke (n = 10/group) showed elevated ilealCxcl2(p = 0,0075) and colonicKcmRNA levels (p = 0,0186), whereas TRPV1 mRNA and protein levels were elevated in the ileum (p = 0,0315). Although cigarette smoke exposure prior to trinitrobenzene sulphonic acid administration did not alter disease activity, increased pro-inflammatory cytokine production was observed in the distal colon (Kc: p = 0,0273; Cxcl2: p = 0,104; Il1-beta: p = 0,0796), in parallel with the increase ofTrpv1mRNA (p < 0,001). We infer that CS affects pro-inflammatory cytokine expression in healthy and inflamed gut, and that the simultaneous modulation of TRPV1 may point to a potential involvement of TRPV1 in cigarette smoke-induced production of inflammatory mediators.

• Transient receptor potential channels in intestinal inflammation : what is the impact of cigarette smoking?

  2017

  Inflammatory bowel disease (IBD) is characterized by severe gastrointestinal inflammation and results from a complex interplay between genetic and environmental factors. IBD includes two prominent subtypes: Crohn's disease (CD) and ulcerative colitis (UC). One of the main risk factors for the development of CD is cigarette smoking, while UC is rather a disease of ex-smokers. To date, many of the mechanisms underlying the immune imbalance in IBD and the involvement of cigarette smoke (CS) are incompletely understood. Transient receptor potential (TRP) proteins are non-selective cation channels that, upon activation, lead to plasma membrane depolarization and, in general, to Ca2+ influx. TRP channels of the ankyrin and vanilloid family, expressed by sensory neurons in the central and enteric nervous systems, have been extensively studied in the context of intestinal inflammation. Moreover, recent advances made on the role of non-neuronal expressed TRP channels shed light on the involvement of epithelial cells in inflammatory processes. This review focuses on how CS may impact TRP channel function in intestinal inflammation. Firstly, we discuss the current knowledge on neuronal TRP channels, known to be linked to IBD, in health, immune homeostasis and intestinal inflammation. Subsequently, we address how TRP channels are activated by CS and its components in other organ systems and also hypothesize on the potential implications for CS-mediated TRP channel activation in gut inflammation.

• The Effect of Cigarette Smoke Exposure on the Development of Inflammation in Lungs, Gut and Joints of TNFΔARE Mice

  2015

  The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases, such as Crohn's disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE mice; in which a systemic TNF-α overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however depend on the duration of CS exposure.

• Chronic cigarette smoke exposure induces microbial and inflammatory shifts and mucin changes in the murine gut

  2016

  Inflammatory bowel diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome, mucus layer composition and immune factors in conventional mice. We compared smoke-exposed with air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, the mRNA expression of Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.