Therapeutic responses to Roseomonas mucosa in atopic dermatitis may involve lipid-mediated TNF-related epithelial repair

The role of the skin microbiota in the modulation of cutaneous inflammation-Lessons from the gut

Inflammation is a vital defense mechanism used to protect the body from invading pathogens, but dysregulation can lead to chronic inflammatory disorders such as psoriasis and atopic dermatitis. Differences in microbiota composition have been observed in patients with inflammatory skin conditions compared with healthy individuals, particularly within lesions. There is also increasing evidence accumulating to support the notion that the microbiome contributes to the onset or modulates the severity of inflammatory diseases. Despite the known protective effects of orally administered lactic acid bacteria against inflammation, few studies have investigated the potential protective effects of topical application of bacteria on skin health and even fewer have looked at the potential anti-inflammatory effects of skin commensals. If lack of diversity and reduction in the abundance of specific commensal strains is observed in inflammatory skin lesions, and it is known that commensal bacteria can produce anti-inflammatory compounds, we suggest that certain members of the skin microbiota have anti-inflammatory properties that can be harnessed for use as topical therapeutics in inflammatory skin disorders.

Use of Autologous Bacteriotherapy to Treat Staphylococcus aureus in Patients With Atopic Dermatitis: A Randomized Double-blind Clinical Trial

IMPORTANCE

Atopic dermatitis (AD) can be negatively affected by Staphylococcus aureus. The skin microbiome of AD is deficient in coagulase-negative Staphylococcus (CoNS) that can kill S aureus.

OBJECTIVE

To evaluate if the antimicrobial-producing CoNS (CoNS-AM+) of a patient with AD can be autologously reintroduced to the same patient to inhibit survival of S aureus and improve clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, vehicle-controlled, single-center randomized clinical trial of 11 adult patients with moderate to severe AD who were randomized to receive either an autologous CoNS-AM+ (n = 5) or the vehicle (n = 6) was conducted between April 2016 and May 2018. The data were analyzed from May 2018 to July 2019.

INTERVENTIONS

Autologous CoNS-AM+ was isolated from swabs that were obtained from the nonlesional skin of each patient with AD, expanded by culture, and then reapplied topically to the forearms at a concentration of 107 colony-forming units/g.

MAIN OUTCOMES AND MEASURES

The primary end point of this study was to assess S aureus abundance after 1 week of application of autologous CoNS-AM+ on patients with AD by culture-based and DNA-based methods. The secondary end points were to assess the safety and clinical outcomes.

RESULTS

Eleven patients (4 men [36.4%] and 7 women [63/6%]) were recruited based on the inclusion criteria. There were no serious adverse events in groups treated with autologous CoNS-AM+ or the vehicle. Staphylococcus aureus colonization on lesional skin at the end of treatment on patients who were treated with autologous CoNS-AM+ (mean of log10 ratio to baseline, -1.702; 95% CI, -2.882 to -0.523) was reduced by 99.2% compared with vehicle treatment (mean of log10 ratio to baseline, 0.671; 95% CI, -0.289 to 1.613; P = .01) and persisted for 4 days after treatment (CoNS-AM+: mean of log10 ratio to baseline, -1.752; 95% CI, -3.051 to -0.453; vehicle: mean of log10 ratio to baseline, -0.003; 95% CI, -1.083 to 1.076; P = .03). Importantly, local Eczema Area And Severity Index scores that were assessed at day 11 on patients who received CoNS-AM+ (mean of percentage change, -48.45; 95% CI, -84.34 to -12.55) were significantly improved compared with vehicle treatment (mean of percentage change, -4.52; 95% CI, -36.25 to 27.22; P = .04).

CONCLUSIONS AND RELEVANCE

The data from this randomized clinical trial suggest that bacteriotherapy with an autologous strain of skin commensal bacteria can safely decrease S aureus colonization and improve disease severity. Although larger studies will be needed, this personalized approach for S aureus reduction may provide an alternative treatment for patients with AD beyond antibiotics, immunosuppression, and immunomodulation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03158012.

Advances in the Translational Science of Dermatitis

The cycle of converting mechanistic insight into therapeutic interventions is called translational science. It has been relatively sluggish in atopic dermatitis (AD), but finally pathomechanisms have been identified and therapeutic targets selected and refined. From inflammatory mediators, skin barrier enhancement, itch relief, and alteration of the microbiota, several therapies have been proposed and are actively being studied for AD, suggesting an end to the drought of innovation.

Management of Severe Atopic Dermatitis in Pediatric Patients

Atopic dermatitis is a common, chronic inflammatory skin disorder, present in about 12% of children worldwide. Optimizing management of severe atopic dermatitis in pediatric patients is critical to reduce signs of inflammation, alleviate pruritus and sleep disturbance, minimize the development and/or impact of comorbidities, and improve the patient and caregiver's quality of life. Evaluating the longitudinal severity of pediatric atopic dermatitis is an important component of measuring therapeutic response and long-term management, and is different in clinical practice versus clinical trials. This article describes when and how to use different treatments for pediatric patients with severe atopic dermatitis, including topical medications, phototherapy, and systemic medical therapies (traditional immunosuppressants, biologics, and small molecule inhibitors). It also provides recommendations useful in clinical practice for nonpharmacologic interventions for pediatric patients with severe atopic dermatitis.

Targeting Innate Immunity to Combat Cutaneous Stress: The Vitiligo Perspective

Multiple factors are involved in the process leading to melanocyte loss in vitiligo including environmental triggers, genetic polymorphisms, metabolic alterations, and autoimmunity. This review aims to highlight current knowledge on how danger signals released by stressed epidermal cells in a predisposed patient can trigger the innate immune system and initiate a cascade of events leading to an autoreactive immune response, ultimately contributing to melanocyte disappearance in vitiligo. We will explore the genetic data available, the specific role of damage-associated-molecular patterns, and pattern-recognition receptors, as well as the cellular players involved in the innate immune response. Finally, the relevance of therapeutic strategies targeting this pathway to improve this inflammatory and autoimmune condition is also discussed.

Differential responses to folic acid in an established keloid fibroblast cell line are mediated by JAK1/2 and STAT3

Keloids are a type of disordered scar formation which not only show heterogeneity between individuals and within the scar itself, but also share common features of hyperproliferation, abnormal extra-cellular matrix deposition and degradation, as well as altered expression of the molecular markers of wound healing. Numerous reports have established that cells from keloid scars display Warburg metabolism—a form of JAK2/STAT3-induced metabolic adaptation typical of rapidly dividing cells in which glycolysis becomes the predominant source of ATP over oxidative phosphorylation (OxPhos). Using the JAK1/2 inhibitor ruxolitinib, along with cells from patients with STAT3 loss of function (STA3 LOF; autosomal dominant hyper IgE syndrome) we examined the role of JAK/STAT signaling in the hyperproliferation and metabolic dysregulation seen in keloid fibroblasts. Although ruxolitinib inhibited hyperactivity in the scratch assay in keloid fibroblasts, it paradoxically exacerbated the hyper-glycolytic state, possibly by further limiting OxPhos via alterations in mitochondrial phosphorylated STAT3 (pSTAT3^Ser727). In healthy volunteer fibroblasts, folic acid exposure recapitulated the exaggerated closure and hyper-glycolytic state of keloid fibroblasts through JAK1/2- and STAT3-dependent pathways. Although additional studies are needed before extrapolating from a representative cell line to keloids writ large, our results provide novel insights into the metabolic consequences of STAT3 dysfunction, suggest a possible role for folate metabolism in the pathogenesis of keloid scars, and offer in vitro pre-clinical data supporting considerations of clinical trials for ruxolitinib in keloid disorder.

Epithelial-Mesenchymal Transition in Atopy: A Mini-Review

Atopic diseases, particularly atopic dermatitis (AD), asthma, and allergic rhinitis (AR) share a common pathogenesis of inflammation and barrier dysfunction. Epithelial to mesenchymal transition (EMT) is a process where epithelial cells take on a migratory mesenchymal phenotype and is essential for normal tissue repair and signal through multiple inflammatory pathways. However, while links between EMT and both asthma and AR have been demonstrated, as we outline in this mini-review, the literature investigating AD and EMT is far less well-elucidated. Furthermore, current studies on EMT and atopy are mostly animal models or ex vivo studies on cell cultures or tissue biopsies. The literature covered in this mini-review on EMT-related barrier dysfunction as a contributor to AD as well as the related (perhaps resultant) atopic diseases indicates a potential for therapeutic targeting and carry treatment implications for topical steroid use and environmental exposure assessments. Further research, particularly in vivo studies, may greatly advance the field and translate into benefit for patients and families.

Tumor Necrosis Factor Receptors: Pleiotropic Signaling Complexes and Their Differential Effects

Since its discovery in 1975, TNFα has been a subject of intense study as it plays significant roles in both immunity and cancer. Such attention is well deserved as TNFα is unique in its engagement of pleiotropic signaling via its two receptors: TNFR1 and TNFR2. Extensive research has yielded mechanistic insights into how a single cytokine can provoke a disparate range of cellular responses, from proliferation and survival to apoptosis and necrosis. Understanding the intracellular signaling pathways induced by this single cytokine via its two receptors is key to further revelation of its exact functions in the many disease states and immune responses in which it plays a role. In this review, we describe the signaling complexes formed by TNFR1 and TNFR2 that lead to each potential cellular response, namely, canonical and non-canonical NF-κB activation, apoptosis and necrosis. This is followed by a discussion of data from in vivo mouse and human studies to examine the differential impacts of TNFR1 versus TNFR2 signaling.