A plant-derived glucocorticoid receptor modulator attenuates inflammation without provoking ligand-induced resistance

Background: Acquired resistance to glucocorticoids constitutes a major clinical challenge, often overlooked in the search for improved alternatives to classic steroids. We sought to unravel how two glucocorticoid receptor-activating compounds, dexamethasone and Compound A, influence glucocorticoid receptor levels and how this can be correlated to their gene regulatory potential. Methods: Compound A and dexamethasone were applied in a short-term and long-term treatment protocol. By quantitative PCR analysis in fibroblast-like synoviocytes (FLS) the gene regulatory potential of both compounds in the two experimental conditions was analysed. A parallel Western blot assay revealed the glucocorticoid receptor protein levels in both conditions (ex vivo). In addition, this study examined the effect of systemic administration of dexamethasone and Compound A, in concentrations effective to inhibit collagen-induced arthritis, in DBA/1 mice on glucocorticoid receptor levels (in vivo). Results: Compound A does not induce a homologous downregulation of glucocorticoid receptor in vivo and ex vivo, thereby retaining its anti-inflammatory effects after prolonged treatment in FLS. This is in sharp contrast to dexamethasone, showing a direct link between prolonged dexamethasone treatment, decreasing glucocorticoid receptor levels, and the abolishment of inflammatory gene repression in FLS. It was also observed that the acquired low receptor levels after prolonged dexamethasone treatment are still sufficient to sustain the transactivation of endogenous glucocorticoid-responsive element-driven genes in FLS, a mechanism partly held accountable for the metabolic side-effects. Conclusion: Compound A is less likely to evoke therapy resistance, as it does not lead to homologous glucocorticoid receptor downregulation, which is in contrast to classic glucocorticoids

HDAC inhibitors in experimental liver and kidney fibrosis

Histone deacetylase (HDAC) inhibitors have been extensively studied in experimental models of cancer, where their inhibition of deacetylation has been proven to regulate cell survival, proliferation, differentiation and apoptosis. This in turn has led to the use of a variety of HDAC inhibitors in clinical trials. In recent years the applicability of HDAC inhibitors in other areas of disease has been explored, including the treatment of fibrotic disorders. Impaired wound healing involves the continuous deposition and cross-linking of extracellular matrix governed by myofibroblasts leading to diseases such as liver and kidney fibrosis; both diseases have high unmet medical needs which are a burden on health budgets worldwide. We provide an overview of the potential use of HDAC inhibitors against liver and kidney fibrosis using the current understanding of these inhibitors in experimental animal models and in vitro models of fibrosis

Impact of COVID-19 pandemic on the management of patients with RA: a survey of rheumatologists in six European countries

OBJECTIVE: We aimed to describe, from the perspective of rheumatologists in Europe, how the coronavirus disease 2019 (COVID-19) pandemic has impacted their management of people with RA and the continuing medical education of physicians. METHODS: Rheumatologists participating in the Adelphi RA Disease Specific ProgrammeTM in six European countries were contacted in August and September 2020 for a telephone survey. Rheumatologists were asked seven attitudinal questions on changes to patient management, prescription behaviour and continuing education owing to COVID-19. Results were summarized with descriptive statistics. RESULTS: The telephone survey was completed by 284 rheumatologists. The most commonly reported changes to patient management were increased utilization of video/telephone consultations (66.5% of respondents), fewer visits (58.5%) and limiting physical contact (58.1%). Furthermore, 67.9% of rheumatologists who indicated that prescribing behaviour had changed switched their patients to self-administered medication, and 60.7% reported not starting patients on targeted synthetic DMARDs, biologic originator DMARDs or biosimilar DMARDs. In total, 57.6% of rheumatologists believed that changes in management would persist. Rheumatologists reported that 38.0% of patients expressed concerns about how COVID-19 would impact treatment, including access to treatment and the risk of infection. The biggest impact on rheumatologist education was a switch to online training and conferences. CONCLUSION: All countries saw changes in patient management and prescribing behaviour, including the rapid uptake of telemedicine. It is important that the international rheumatology community learns from these experiences to prepare better for future pandemics and to address ongoing rheumatologist shortages

Design of an optimized Wilms' tumor 1 (WT1) mRNA construct for enhanced WT1 expression and improved immunogenicity in vitro and in vivo

Tumor antigen-encoding mRNA for dendritic cell (DC)-based vaccination has gained increasing popularity in recent years. Within this context, two main strategies have entered the clinical trial stage: the use of mRNA for ex vivo antigen loading of DCs and the direct application of mRNA as a source of antigen for DCs in vivo. DCs transfected with mRNA-encoding Wilms' tumor 1 (WT1) protein have shown promising clinical results. Using a stepwise approach, we re-engineered a WT1 cDNA-carrying transcription vector to improve the translational characteristics and immunogenicity of the transcribed mRNA. Different modifications were performed: (i) the WT1 sequence was flanked by the lysosomal targeting sequence of dendritic cell lysosomal-associated membrane protein to enhance cytoplasmic expression; (ii) the nuclear localization sequence (NLS) of WT1 was deleted to promote shuttling from the nucleus to the cytoplasm; (iii) the WT1 DNA sequence was optimized in silico to improve translational efficiency; and (iv) this WT1 sequence was cloned into an optimized RNA transcription vector. DCs electroporated with this optimized mRNA showed an improved ability to stimulate WT1-specific T-cell immunity. Furthermore, in a murine model, we were able to show the safety, immunogenicity, and therapeutic activity of this optimized mRNA. This work is relevant for the future development of improved mRNA-based vaccine strategies K

Phenotypical and functional differentiation of natural killer cells and T cell receptor γδ cells

The innate or natural immune system provides a rapid and non-specific response against invading pathogens and tumor cells. This first line of defense contains lymphoid cells, such as natural killer (NK) cells and TCR gd cells. In contrast to lymphocytes of the adaptive or acquired immune system, i. e. B lymphocytes and TCR ab cells, major gaps still exist in understanding the maturation, phenotype and function of TCR gd cells and NK cells. The aim of this study was to elaborate the differentiation, phenotype and function of murine NK cells and TCR gd cells. In chapter 1 we focussed on the phenotypical and functional characteristics of murine fetal NK cells. Contrary to NK cells from adult mice, fetal NK cells have a limited NK receptor repertoire. The only NK receptor transcripts that could be detected were Ly49E and CD94/NKG2. In contrast with adult NK cells, fetal NK cells were not able to kill MHC class I-negative target cells, unless fetal NK cells were triggered via an activating NK receptor (part 1). As serological reagents against Ly49E and CD94/NKG2 were lacking, it was not clear whether Ly49E and CD94/NKG2 receptors were expressed at the cell surface of NK cells. Therefore, we generated anti-Ly49E and anti-CD94/NKG2 mAbs (part 2). Using both mAbs in flow cytometry, the phenotype of mouse fetal and adult NK cells was further extended. In part 3, we studied the NK differentiation potential of fetal versus adult hematopoietic precursor cells and analyzed the ordered expression of NK receptors on developing NK cells in vitro and in vivo. In the following chapter, the phenotypic and functional differentiation of gd T cells was studied. In part 1 we studied the intrathymic maturation of human gd T cells, and demonstrate that CD1 is a hallmark to distinguish immature from mature gd thymocytes. In part 2, the generated anti-Ly49E and anti-CD94/NKG2 mAbs have been used to demonstrate the phenotypical and functional relationship between NK cells and one subset of murine TCR gd cells, namely Vg3 T cells. We demonstrate that mature, but not immature, Vg3 T cells express both Ly49E and CD94/NKG2 receptors, and that the cytotoxic activity of Vg3 T cells can be inhibited by the inhibitory CD94/NKG2 receptor. In conclusion we can conclude that this work contributed to a better understanding in the phenotype, function, and differentiation of both NK cells and TCR gd cells

Adjustments in Food Choices and Physical Activity during Lockdown by Flemish Adults

Background: On Wednesday 18/03/2020 Belgium was placed in lockdown in order to curb the spread of COVID-19. Lockdown can lead to loneliness, boredom, anger, anxiety and depression, which in turn have an influence on food choices and physical activity (PA). This study aims to map the adjustments in food choices and PA by Flemish adults during lockdown. Methods: Chi square tests were performed to investigate the relationship between adjustments in food choices, PA and demographic variables. Results: A total of 1.129 respondents filled in the online questionnaire, aged between 18 and 81 years. The healthiest food choices were made by respondents living alone during lockdown, whilst people cohabiting with others increased their PA significantly. Moreover, the dietary adjustments of adults living with children evolved more favourably to healthier choices then those cohousing with other adults. However, respondents living with other adults showed a more favourable pattern regarding adjustments in PA. The strongest increase in sedentary behaviour was observed in students. Conclusions: This study shows the impact of lockdown on both PA and food choices, where healthier adjustments were observed in PA and respondents were prone to consume unhealthier food