Inflammatory cytokines and biofilm production sustain Staphylococcus aureus outgrowth and persistence: A pivotal interplay in the pathogenesis of Atopic Dermatitis

Individuals with Atopic dermatitis (AD) are highly susceptible to Staphylococcus aureus colonization. However, the mechanisms driving this process as well as the impact of S. aureus in AD pathogenesis are still incompletely understood. In this study, we analysed the role of biofilm in sustaining S. aureus chronic persistence and its impact on AD severity. Further we explored whether key inflammatory cytokines overexpressed in AD might provide a selective advantage to S. aureus. Results show that the strength of biofilm production by S. aureus correlated with the severity of the skin lesion, being significantly higher (P < 0.01) in patients with a more severe form of the disease as compared to those individuals with mild AD. Additionally, interleukin (IL)-β and interferon γ (IFN-γ), but not interleukin (IL)-6, induced a concentration-dependent increase of S. aureus growth. This effect was not observed with coagulase-negative staphylococci isolated from the skin of AD patients. These findings indicate that inflammatory cytokines such as IL1-β and IFN-γ, can selectively promote S. aureus outgrowth, thus subverting the composition of the healthy skin microbiome. Moreover, biofilm production by S. aureus plays a relevant role in further supporting chronic colonization and disease severity, while providing an increased tolerance to antimicrobials

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Baricitinib safety for events of special interest in populations at risk: analysis from randomised trial data across rheumatologic and dermatologic indications

Introduction: Baricitinib, a Janus kinase (JAK) 1/2 inhibitor, is an approved treatment for rheumatoid arthritis (RA), atopic dermatitis (AD), and alopecia areata (AA). Further characterisation of adverse events of special interest (AESI) for JAK inhibitors in at-risk populations will improve benefit-risk assessment for individual patients and diseases. Methods: Data were pooled from clinical trials and long-term extensions in moderate-to-severe active RA, moderate-to-severe AD, and severe AA. Incidence rates (IR) per 100 patient-years of major adverse cardiovascular event (MACE), malignancy, venous thromboembolism (VTE), serious infection, and mortality were calculated for patients with low risk (younger than 65 years with no specified risk factors), and patients at risk (≥1 of: aged 65 years or older, atherosclerotic cardiovascular disease, diabetes mellitus, hypertension, current smoking, HDL cholesterol <40 mg/dL, BMI ≥30 kg/m2, poor mobility on EQ-5D, or history of malignancy). Results: Datasets included baricitinib exposure up to 9.3 years with 14744 person-years of exposure (PYE) (RA), 3.9 years with 4628 PYE (AD), and 3.1 years with 1868 PYE (AA). In patients with low risk (RA: 31%, AD: 48%, AA: 49%), IRs for MACE (0.05, 0.04, 0), malignancies (0.20, 0.13, 0), VTE (0.09, 0.04, 0), serious infection (1.73, 1.18, 0.6), and mortality (0.04, 0, 0) in the RA, AD, and AA datasets, respectively, were low. In patients at risk (RA: 69%, AD: 52%, AA: 51%), IRs were for MACE (0.70, 0.25, 0.10), malignancies (1.23, 0.45, 0.31), VTE (0.66, 0.12, 0.10), serious infection (2.95, 2.30, 1.05), and mortality (0.78, 0.16, 0) for RA, AD, and AA datasets, respectively. Conclusion: Populations with low risk have low incidence of the examined JAK inhibitor-related AESI. In the dermatologic indications, incidence is also low for patients at risk. Considering individual disease burden, risk factors, and response to treatment is relevant to make informed decisions for individual patients treated with baricitinib

Quantification of indoleamine 2,3-dioxygenase gene induction in atopic and non-atopic monocytes after ligation of the high-affinity receptor for IgE, FcɛRI and interferon-γ stimulation

Antigen-presenting cells (APCs) are crucial in regulating the outcome of T cell responses. Certain APCs are able to down-regulate T cell proliferation in vitro by inducing the enzyme indoleamine 2,3-dioxygenase (IDO) upon interferon-γ (IFN-γ) stimulation. IDO is the rate-limiting enzyme in the catabolism of the essential amino acid tryptophan. A lack of extracellular tryptophan creates environments in which cells become starved for this amino acid. The high-affinity receptor for IgE, FcɛRI, is the principal receptor for the binding of specific IgE in type I-mediated allergies. We demonstrated recently that IDO is overexpressed in FcɛRI-stimulated monocytes. In the present study, we performed quantification of IDO gene induction after treatment of atopic (FcɛRI(high)) and non-atopic (FcɛRI(low/–)) monocytes with IgE/anti-IgE and IFN-γ. By quantitative PCR ELISA, we found IDO molecule induction in atopic monocytes was enhanced about 50-fold over non-atopic monocytes after ligation of FcɛRI. Stimulation with IFN-γ at a concentration of 100 U/ml in culture medium caused an increase in IDO gene copy numbers in atopics of about fourfold over that of non-atopics. This comparative quantification study demonstrates clearly the regulation of IDO gene expression by FcɛRI and discloses differences thereof in atopic and non-atopic cells upon inflammatory stimuli