Browsing by Author "Alberts, Janneke"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    The role of estrogen receptors in fibrosis: in search of therapeutics
    (Stellenbosch : Stellenbosch University, 2024-02) Alberts, Janneke; Smith, Carine; Ollewagen, Tracey; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine. Division of Clinical Pharmacology.
    ENGLISH ABSTRACT: Background: Autoimmune rheumatic diseases, affecting 5-8% of people globally, exhibit a 2:1 female prevalence bias, influencing severity and prognosis. Chronic inflammation leads to immune complex formation, which causes vessel occlusion, and resulting in fibrosis, contributing to cardiovascular diseases, particularly myocarditis. Fibrosis - driven by activated fibroblasts - results from extracellular matrix dysregulation, causing tissue scarring and organ dysfunction. Therefore, investigating antifibrotic interventions is crucial for global healthcare. 17β-estradiol (E2), the predominant female hormone, has the potential to modulate fibrosis, but literature in this niche is contradictory. Zebrafish have been identified as an ideal model for studying sex bias in autoimmune rheumatic-related myocarditis, exploring the role of E2 in chronic inflammation and fibrosis. Methods: To elucidate underlying mechanisms, a multidisciplinary approach was imperative. Employing diverse model systems, the thesis incorporated two pilot studies. The initial pilot study utilised male human dermal fibroblasts (HDFs) in vitro to assess the impact of E2 on cell function linked to fibrotic outcome. Cell viability and fibronectin production were assessed after 24 hours (h) E2- exspoure relative to that of untreated cells. Subsequently, a second pilot study evaluated behavioural outcomes in larval zebrafish, in response to exposure of a range of E2 dosages for 60 h, informing the selection of an appropriate, potentially beneficial, E2 concentration for the main experiment. A significant innovation was the establishment of a novel larval zebrafish myocarditis model, by means of microinjection with a sclerosing agent (bleomycin). Using this model, the effect of added E2 and modulation of estrogen receptor (ER) signalling on fibrosis was determined by staining for collagen (Masson-Goldner Trichrome) and vimentin (immunofluorescence staining). Results: Results generated in HDFs elucidated that treatment with E2 did not significantly alter the fibroblast viability or fibronectin production. Microinjected zebrafish larvae exhibited lower basal activity levels than controls (p