Using systems medicine to identify a therapeutic agent with potential for repurposing in inflammatory bowel disease

ObjectiveInflammatory bowel diseases cause significant morbidity and mortality. Aberrant NF-κB signalling is strongly associated with these conditions, and several established drugs influence the NF-κB signalling network to exert their effect. This study aimed to identify drugs which alter NF-κB signalling and may be repositioned for use in inflammatory bowel disease.DesignThe SysmedIBD consortium established a novel drug-repurposing pipeline based on a combination of in-silico drug discovery and biological assays targeted at demonstrating an impact on NF-kappaB signalling, and a murine model of IBD.ResultsThe drug discovery algorithm identified several drugs already established in IBD, including corticosteroids. The highest-ranked drug was the macrolide antibiotic Clarithromycin, which has previously been reported to have anti-inflammatory effects in aseptic conditions. Clarithromycin's effects were validated in several experiments: it influenced NF-κB mediated transcription in murine peritoneal macrophages and intestinal enteroids; it suppressed NF-κB protein shuttling in murine reporter enteroids; it suppressed NF-κB (p65) DNA binding in the small intestine of mice exposed to LPS, and it reduced the severity of dextran sulphate sodium-induced colitis in C57BL/6 mice. Clarithromycin also suppressed NF-κB (p65) nuclear translocation in human intestinal enteroids.ConclusionsThese findings demonstrate that in-silico drug repositioning algorithms can viably be allied to laboratory validation assays in the context of inflammatory bowel disease; and that further clinical assessment of clarithromycin in the management of inflammatory bowel disease is required

Correlation between immunoglobulin dose administered and plasma neutralization of streptococcal superantigens in patients with necrotizing soft tissue infections.

Analyses of plasma collected pre- and post-administration of intravenous immunoglobulin G (IVIG) from patients with Group A Streptococcus necrotizing soft tissue infections demonstrated a negative correlation between IVIG dose and toxin-triggered T-cell proliferation (r=-0.67, p<0.0001). One 25g-dose IVIG was sufficient to yield patient plasma neutralizing activity against streptococcal superantigens

Disease Activity Patterns of Crohn's Disease in the First Ten Years After Diagnosis in the Population-based IBD South Limburg Cohort

BACKGROUND AND AIMS: Real-life data on long-term disease activity in Crohn's disease [CD] are scarce. Most studies describe disease course by using proxies, such as drug exposure, need for surgery or hospitalisations, and disease progression. We aimed to describe disease course by long-term disease activity and to identify distinctive disease activity patterns in the population-based IBD South Limburg cohort [IBDSL]. METHODS: All CD patients in IBDSL with ≥10 years follow-up [n = 432] were included. Disease activity was defined for each yearly quarter by mucosal inflammation on endoscopy or imaging, hospitalisation, surgery, or treatment adjustment for increased symptoms. Six distinct disease activity clusters were defined. Subsequently, the associations between clinical characteristics and the patterns were assessed using multivariable logistic regression models. RESULTS: On average, patients experienced 5.44 (standard deviation [SD] 3.96) quarters of disease activity during the first 10 years after diagnosis. Notably, 28.2% of the patients were classified to a quiescent pattern [≤2 active quarters in 10 years], and 89.8% of those never received immunomodulators nor biologics. Surgery at diagnosis (odds ratio [OR] 2.99; 95% confidence interval [CI] 1.07-8.34) and higher age [OR 1.03; 95% CI 1.01-1.06] were positively associated with the quiescent pattern, whereas inverse associations were observed for ileocolonic location [OR 0.44; 95% CI 0.19-1.00], smoking [OR 0.43; 95% CI 0.24-0.76] and need for steroids <6 months [OR 0.24; 95% CI 0.11-0.52]. CONCLUSIONS: Considering long-term disease activity, 28.2% of CD patients were classified to a quiescent cluster. Given the complex risk-benefit balance of immunosuppressive drugs, our findings underline the importance of identifying better predictive markers to prevent both over-treatment and under-treatment.</p

Risk factors and Predictors of Mortality in Streptococcal Necrotizing Soft-Tissue Infections: A Multicenter Prospective Study.

Background Necrotizing soft-tissue infections (NSTI) are life-threatening conditions often caused by β-hemolytic streptococci, group A streptococcus (GAS) in particular. Optimal treatment is contentious. The INFECT cohort includes the largest set of prospectively enrolled streptococcal NSTI cases to date. Methods From the INFECT cohort of 409 adults admitted with NSTI to five clinical centers in Scandinavia, patients culture-positive for GAS or Streptococcus dysgalactiae (SD) were selected. Risk factors were identified by comparison with a cohort of non-necrotizing streptococcal cellulitis. The impact of baseline factors and treatment on 90-day mortality was explored using Lasso regression. Whole-genome sequencing of bacterial isolates was used for emm typing and virulence gene profiling. Results The 126 GAS NSTI cases and 27 cases caused by SD constituted 31% and 7% of the whole NSTI cohort, respectively. When comparing to non-necrotizing streptococcal cellulitis, streptococcal NSTI was associated to blunt trauma, absence of pre-existing skin lesions, and a lower BMI. Septic shock was significantly more frequent in GAS (65%) compared to SD (41%) and polymicrobial, non-streptococcal NSTI (46%). Age, male sex, septic shock, and no administration of intravenous immunoglobulin (IVIG) were among factors associated with 90-day mortality. Predominant emm types were emm1, emm3 and emm28 in GAS and stG62647 in SD

Material removal correction in residual stress analyses by X-ray diffraction: a GFAC project

International audienc

Effects of Human RelA Transgene on Murine Macrophage Inflammatory Responses

The NFκB transcription factors are major regulators of innate immune responses, and NFκB signal pathway dysregulation is linked to inflammatory disease. Here, we utilised bone marrow-derived macrophages from the p65-DsRedxp/IκBα-eGFP transgenic strain to study the functional implication of xenogeneic (human) RelA(p65) protein introduced into the mouse genome. Confocal imaging showed that human RelA is expressed in the cells and can translocate to the nucleus following activation of Toll-like receptor 4. RNA sequencing of lipid A-stimulated macrophages, revealed that human RelA impacts on murine gene transcription, affecting both non-NFκB and NFκB target genes, including immediate-early and late response genes, e.g., Fos and Cxcl10. Validation experiments on NFκB targets revealed markedly reduced mRNA levels, but similar kinetic profiles in transgenic cells compared to wild-type. Enrichment pathway analysis of differentially expressed genes revealed interferon and cytokine signaling were affected. These immune response pathways were also affected in macrophages treated with tumor necrosis factor. Data suggests that the presence of xenogeneic RelA protein likely has inhibitory activity, altering specific transcriptional profiles of key molecules involved in immune responses. It is therefore essential that this information be taken into consideration when designing and interpreting future experiments using this transgenic strain

Round robin of external samples for residual stress analyses by X-ray diffraction

International audienc

Necrotizing Soft Tissue Infection Staphylococcus aureus but not S. pyogenes Isolates Display High Rates of Internalization and Cytotoxicity Toward Human Myoblasts

Necrotizing soft tissue infections (NSTIs) caused by group A Streptococcus (GAS) and occasionally by Staphylococcus aureus (SA) frequently involve the deep fascia and often lead to muscle necrosis. Methods: To assess the pathogenicity of GAS and S. aureus for muscles in comparison to keratinocytes, adhesion and invasion of NSTI-GAS and NSTI-SA isolates were assessed in these cells. Bloodstream infections (BSI-SA) and noninvasive coagulase-negative staphylococci (CNS) isolates were used as controls. Results: NSTI-SA and BSI-SA exhibited stronger internalization into human keratinocytes and myoblasts than NSTI-GAS or CNS. S. aureus internalization reached over 30% in human myoblasts due to a higher percentage of infected myoblasts (>11%) as compared to keratinocytes (<3%). Higher cytotoxicity for myoblasts of NSTI-SA as compared to BSI-SA was attributed to higher levels of psmα and RNAIII transcripts in NSTI-SA. However, the 2 groups were not discriminated at the genomic level. The cellular basis of high internalization rate in myoblasts was attributed to higher expression of α5β1 integrin in myoblasts. Major contribution of FnbpAB-integrin α5β1 pathway to internalization was confirmed by isogenic mutants. Conclusions: Our findings suggest a factor in NSTI-SA severity is the strong invasiveness of S. aureus in muscle cells, a property not shared by NSTI-GAS isolates