Injury, dysbiosis, and filaggrin deficiency drive skin inflammation through keratinocyte IL-1α release.

BACKGROUND: Atopic dermatitis (AD) is associated with epidermal barrier defects, dysbiosis, and skin injury caused by scratching. In particular, the barrier-defective epidermis in patients with AD with loss-of-function filaggrin mutations has increased IL-1α and IL-1ß levels, but the mechanisms by which IL-1α, IL-1ß, or both are induced and whether they contribute to the aberrant skin inflammation in patients with AD is unknown. OBJECTIVE: We sought to determine the mechanisms through which skin injury, dysbiosis, and increased epidermal IL-1α and IL-1ß levels contribute to development of skin inflammation in a mouse model of injury-induced skin inflammation in filaggrin-deficient mice without the matted mutation (ft/ft mice). METHODS: Skin injury of wild-type, ft/ft, and myeloid differentiation primary response gene-88-deficient ft/ft mice was performed, and ensuing skin inflammation was evaluated by using digital photography, histologic analysis, and flow cytometry. IL-1α and IL-1ß protein expression was measured by means of ELISA and visualized by using immunofluorescence and immunoelectron microscopy. Composition of the skin microbiome was determined by using 16S rDNA sequencing. RESULTS: Skin injury of ft/ft mice induced chronic skin inflammation involving dysbiosis-driven intracellular IL-1α release from keratinocytes. IL-1α was necessary and sufficient for skin inflammation in vivo and secreted from keratinocytes by various stimuli in vitro. Topical antibiotics or cohousing of ft/ft mice with unaffected wild-type mice to alter or intermix skin microbiota, respectively, resolved the skin inflammation and restored keratinocyte intracellular IL-1α localization. CONCLUSIONS: Taken together, skin injury, dysbiosis, and filaggrin deficiency triggered keratinocyte intracellular IL-1α release that was sufficient to drive chronic skin inflammation, which has implications for AD pathogenesis and potential therapeutic targets.

Targeting Notch1 and IKKα Enhanced NF-κB Activation in CD133+ Skin Cancer Stem Cells.

Cancer stem-like cells are hypothesized to be the major tumor-initiating cell population of human cutaneous squamous cell carcinoma (cSCC), but the landscape of molecular alterations underpinning their signaling and cellular phenotypes as drug targets remains undefined. In this study, we developed an experimental pipeline to isolate a highly enriched CD133+CD31-CD45-CD61-CD24- (CD133+) cell population from primary cSCC specimens by flow cytometry. The CD133+ cells show enhanced stem-like phenotypes, which were verified by spheroid and colony formation in vitro and tumor generation in vivo Gene expression profiling of CD133+/- cells was compared and validated, and differentially expressed gene signatures and top pathways were identified. CD133+ cells expressed a repertoire of stemness and cancer-related genes, including NOTCH and NOTCH1-mediated NF-κB pathway signaling. Other cancer-related genes from WNT, growth factor receptors, PI3K/mTOR, STAT pathways, and chromatin modifiers were also identified. Pharmacologic and genetic targeting of NOTCH1, IKKα, RELA, and RELB modulated NF-κB transactivation, the CD133+ population, and cellular and stemness phenotypes. Immunofluorescent staining confirmed colocalization of CD133+ and IKKα expression in SCC tumor specimens. Our functional, genetic, and pharmacologic studies uncovered a novel linkage between NOTCH1, IKKα, and NF-κB pathway activation in maintaining the CD133+ stem SCC phenotypes. Studies investigating markers of activation and modulators of NOTCH, IKK/NF-κB, and other pathways regulating these cancer stem gene signatures could further accelerate the development of effective therapeutic strategies to treat cSCC recurrence and metastasis. Mol Cancer Ther; 17(9); 2034-48. ©2018 AACR.

Clonally expanded γδ T cells protect against Staphylococcus aureus skin reinfection.

The mechanisms that mediate durable protection against Staphylococcus aureus skin reinfections are unclear, as recurrences are common despite high antibody titers and memory T cells. Here, we developed a mouse model of S. aureus skin reinfection to investigate protective memory responses. In contrast with WT mice, IL-1ß-deficient mice exhibited poor neutrophil recruitment and bacterial clearance during primary infection that was rescued during secondary S. aureus challenge. The γδ T cells from skin-draining LNs utilized compensatory T cell-intrinsic TLR2/MyD88 signaling to mediate rescue by trafficking and producing TNF and IFN-γ, which restored neutrophil recruitment and promoted bacterial clearance. RNA-sequencing (RNA-seq) of the LNs revealed a clonotypic S. aureus-induced γδ T cell expansion with a complementarity-determining region 3 (CDR3) aa sequence identical to that of invariant Vγ5+ dendritic epidermal T cells. However, this T cell receptor γ (TRG) aa sequence of the dominant CDR3 sequence was generated from multiple gene rearrangements of TRGV5 and TRGV6, indicating clonotypic expansion. TNF- and IFN-γ-producing γδ T cells were also expanded in peripheral blood of IRAK4-deficient humans no longer predisposed to S. aureus skin infections. Thus, clonally expanded γδ T cells represent a mechanism for long-lasting immunity against recurrent S. aureus skin infections.

Staphylococcus aureus Epicutaneous Exposure Drives Skin Inflammation via IL-36-Mediated T Cell Responses.

Staphylococcus aureus colonization contributes to skin inflammation in diseases such as atopic dermatitis, but the signaling pathways involved are unclear. Herein, epicutaneous S. aureus exposure to mouse skin promoted MyD88-dependent skin inflammation initiated by IL-36, but not IL-1α/ß, IL-18, or IL-33. By contrast, an intradermal S. aureus challenge promoted MyD88-dependent host defense initiated by IL-1ß rather than IL-36, suggesting that different IL-1 cytokines trigger MyD88 signaling depending on the anatomical depth of S. aureus cutaneous exposure. The bacterial virulence factor PSMα, but not α-toxin or δ-toxin, contributed to the skin inflammation, which was driven by IL-17-producing γδ and CD4+ T cells via direct IL-36R signaling in the T cells. Finally, adoptive transfer of IL-36R-expressing T cells to IL-36R-deficient mice was sufficient for mediating S. aureus-induced skin inflammation. Together, this study defines a previously unknown pathway by which S. aureus epicutaneous exposure promotes skin inflammation involving IL-36R/MyD88-dependent IL-17 T cell responses.

Interleukin-17A (IL-17A) and IL-17F Are Critical for Antimicrobial Peptide Production and Clearance of Staphylococcus aureus Nasal Colonization.

Approximately 20% of the population is persistently colonized by Staphylococcus aureus in the nares. Th17-like immune responses mediated by the interleukin-17 (IL-17) family of cytokines and neutrophils are becoming recognized as relevant host defense mechanisms for resolution of S. aureus mucocutaneous infections. Since antimicrobial peptides are regulated by the IL-17 cytokines, we sought to determine the role of IL-17 cytokines in production of antimicrobial peptides in a murine model of S. aureus nasal carriage. We discovered that nasal tissue supernatants have antistaphylococcal activity, and mice deficient in both IL-17A and IL-17F lost the ability to clear S. aureus nasal colonization. IL-17A was found to be sufficient for nasal mBD-3 production ex vivo and was required for CRAMP, mBD-3, and mBD-14 expression in response to S. aureus colonization in vivo These data were confirmed in a clinical study of nasal secretions in which elevated levels of the human forms of these antimicrobial peptides were found in nasal secretions from healthy human subjects when they were colonized with S. aureus but not in secretions from noncolonized subjects. Together, these data provide evidence for the importance of IL-17A regulation of antimicrobial peptides and IL-17F in the clearance of S. aureus nasal carriage.

Clinical excellence in nephrology: Examples from the published literature.

BACKGROUND: Provision of exceptional medical care is a goal for the medical profession because this is what the public needs and deserves. Academic medical centers that value excellent clinicians may have the best chance to recruit and retain these faculty members. When our institution hoped to launch the Miller Coulson Academy of Clinical Excellence to measure and reward master clinicians, a critical first step was to use rigorous methods to develop a definition of clinical excellence. Published papers have illustrated that this general definition of clinical excellence is applicable to fields of psychiatry, cardiology, and pediatrics. In this manuscript, we apply the definition of clinical excellence to nephrology. Using the same framework, we reviewed the literature to find clinical cases and exemplary nephrologists that highlight the specific domains. This collection of reports in nephrology illustrates that the definition of clinical excellence set forth by the Miller Coulson Academy is highly applicable to physicians caring for individuals with kidney disease. Relating the definition of clinical excellence to renal medicine is worthwhile in that it can help to exemplify the model to which physicians and trainees may seek to aspire. KEY MESSAGE: Many examples of clinical excellence in renal medicine can be found in the published medical literature. The domains of clinical excellence, described by the Miller-Coulson Academy of Clinical Excellence, apply very well to the field of nephrology.

Treatment of severe renal disease in ANCA positive and negative small vessel vasculitis with rituximab.

BACKGROUND/AIMS: Rituximab and glucocorticoids are a non-inferior alternative to cyclophosphamide and glucocorticoid therapy for induction of remission in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) patients with moderate renal disease. The efficacy and safety of this approach in patients with severe renal impairment are unknown. We report the outcomes and safety profile of rituximab and glucocorticoid therapy for induction of remission in patients with AAV and ANCA-negative vasculitis presenting with severe renal disease. METHODS: A multicenter, retrospective, cohort study was conducted between 2005 and 2014. Patients with new or relapsing disease with an estimated glomerular filtration rate (eGFR) of ≤20 ml/min/1.73 m(2) treated with rituximab and glucocorticoid induction with or without plasmapheresis were included. Fourteen patients met the inclusion criteria. The primary outcomes were rate of remission and dialysis independence at 6 months. The secondary outcomes were eGFR at 6 months, end-stage renal disease (ESRD), survival rates and adverse events. RESULTS: All patients were Caucasian, and 57% were male. The mean eGFR was 12 ml/min/1.73 m(2) at diagnosis. All patients achieved remission with a median time to remission of 55 days. Seven patients required dialysis at presentation of which 5 patients recovered renal function and discontinued dialysis by 6-month follow-up. The mean eGFR for the 11 patients without ESRD who completed 6-month follow-up was 33 ml/min/1.73 m(2). Four patients ultimately developed ESRD, and one died during the follow-up period. CONCLUSION: Patients with AAV and severe renal disease achieve high rates of remission and dialysis independence when treated with rituximab and glucocorticoids without cyclophosphamide.

Polydactyly: a review.

Polydactyly of the hand is a difficult problem and poses a unique challenge for the hand surgeon. The embryology of limb development is complex, leading to a host of different phenotypes of polydactyly. Polydactyly can occur in any digit and is described as preaxial, postaxial, and central, based on location. Classification systems exist for each of these locations, which guide treatment options. Surgical treatment needs to address the aesthetic and functional aspect of hand reconstruction. Careful consideration and planning of surgical treatment individualized to each patient is required to obtain the best possible outcome.

Upper extremity golf injuries.

Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.